Having been a prolific scorer for both the youth and reserve sides, he was given his first-team debut in the 1997-98 season during an injury crisis at Bristol City. Unfortunately, it was a disappointing debut for Liam as the Hatters slumped to a 3-0 defeat at Ashton Gate. He was given a few further opportunities during the campaign and he did well without really suggesting that he was ready for that level just yet. However, it was evident from these brief appearances that he had a good future in the game.

He started the 1998-99 season as a first-team regular, appearing in the first match of the campaign, a 1-0 win at Wycombe Wanderers courtesy of a Steve Davis free-kick. However, in August 1998, Liam broke his leg in a 3-1 win at Wigan after a heavy challenge from Latics defender Scott Green. Out for four months, he had to watch agonisingly as the side struggled and sold some of the best players. He returned to the team in a 1-0 home win over Blackpool in February 1999, and was a regular member of the first-team until the end of the season. He appeared on the last day of the campaign, a 1-0 win at Millwall, and made a total of 14 first-team appearances.

He was handed the number 11 squad number by manager Lennie Lawrence for the 1999-00 season and this was an indication to many Hatters supporters that he would begin the season in the starting eleven. However, they were mistaken as Liam was an unused substitute in the first match of the campaign, a 0-0 draw at Notts County. After a substitute appearance in the 2-0 home defeat to Bristol Rovers in the League Cup, he was given a starting place in the home game with Blackpool in August 2000. This was to prove a great decision by manager Lawrence as Liam bagged a brace to help the Hatters to a 3-2 win. He was also named as the man-of-the-match. He scored the winner again in the next match, with an 85th minute goal in the excellent 2-1 win at Reading. He failed to score in the next 3 matches in which he featured, but then scored the clincher in a 3-1 home win over Wrexham as the Hatters were the surprise package in Division Two. Another brace followed in the next home game, a 3-1 win over eventually promoted Gillingham. More quickly followed as he scored another two in two games - in a 1-0 win at Oxford and 4-2 home win over Kingstonian in the FA Cup. However, the Hatters form slumped in November and there was only one goal for Liam, that coming in the last minute of a poor 3-1 defeat at Cambridge United. He was back on the score sheet on December 11th as Luton pulled off a shock 2-2 draw at First Division big-spenders Fulham in the FA Cup 3rd Round. He was to score another 4 goals during the season - two in a 3-1 home win over Reading, one in a 3-1 away win at Cardiff City and the third in a 3-1 win at Chesterfield.

He finished the season as the top scorer with a credible 16-goal haul, but with the bulk of them in the first half of the season. His form undoubtedly dipped during the second half of the season, but a lot of this can probably be attributed to tiredness. After the broken leg he sustained at Wigan early in the 1998-1999 season, the 1999-00 campaign must really be considered his first full season as a first-team professional.

2000-01 was a fairly disappointing season for Liam in that he didn't perform as well as he had done the previous campaign. Although a regular forward under manager Ricky Hill, he failed to score until September 23rd in a 2-3 home defeat to Swindon Town, some 13 matches into the season. He scored again 2 matches later with a late equaliser in a 3-3 draw at Bristol Rovers and again 5 games further on in a 3-4 defeat to Wrexham - a game which Luton had led 3-0. He scored the winner in a televised FA Cup First Round match with Rushden & Diamonds - Lil Fuccillo's first game in charge of the team after Hill's sacking. He was to score 5 more times during the season - in a 3-3 FA Cup Third Round draw with QPR, in a 3-1 win at Notts County (Joe Kinnear's second match in charge), in a 5-3 victory over Swansea City and in defeats to Bury and Bristol City. His 9 goals in all competitions were not the tally he would have been hoping for, and his 7 strikes in the league were nowhere near enough to save Luton from being relegated to the basement division for the first time since 1968.

After turning down a new contract during the summer, Liam stayed at Kenilworth Road on a week-to-week contract. He could have started the season as Luton's main striker, but after turning down the contract offer, Hatters boss Joe Kinnear went out and signed Carl Griffiths from Leyton Orient for £65,000. Griffiths began the season in attack alongside Steve Howard, and with Stuart Douglas and Andrew Fotiadis also competing for a striking berth, Liam struggled to earn a regular place in the side.

His first appearance of the season came in the second game of the campaign, when he came on as a substitute in a 2-1 home win over Cheltenham. A further substitute appearance followed at Exeter, before he started at York in a 2-1 win. He started the next game, a 1-1 home draw with Lincoln, but after failing to impress, he was once more dropped. He played two further matches for Luton, a 3-2 defeat at Dagenham & Redbridge in the LDV Vans Trophy, and as a substitute in a 3-2 defeat at Southend in the FA Cup. With Kinnear purchasing another striker, Dean Crowe, from Stoke, Liam's days at Kenilworth Road were numbered and, after initially turning down an approach from Second Division Colchester, he had a re-think, and looked all set to sign for the U's for a nominal fee at the end of November 2001. However, Liam surprisingly failed a medical and the move to Layer Road was called off.

He returned to Kenilworth Road, but after a couple of weeks, his contract was paid up by mutual consent and he left Bedfordshire in the search for a new club, failing to impress at Gillingham, Sheffield United, Leyton Orient and Clydebank during trial spells. He eventually signed for Conference outfit Stevenage Borough just prior to the 2001-02 transfer deadline day, linking up with ex-Luton assistant manager Wayne Turner, who had just been appointed as the new Stevenage manager.

However, he left Broadhall Way during the summer of the 2002-03 season after 4 appearances and 0 goals and he signed a three-month deal with Bury. His stay at Gigg Lane was only short (8 appearances, 1 goal) and he then joined Boston United for a brief period (3 appearances, 0 goals) before signing for Irish side St. Patrick's Athletic (7 appearances, 0 goals), where he ended the 2002-03 season.

At the end of the campaign, he signed a one-year deal with Division Three York City following a successful trial period at Bootham Crescent and where he was looking to put his disappointing form of the last couple of seasons behind him, and show why he was once rated as a big prospect by Luton.

Liam endured a good start to his York City career as he netted two goals in his opening seven appearances, but injury then curtailed his season and when he returned, he was disappointing and found himself in a side on a dramatic slump that culminated in the Minstermen being relegated from the Football League for the first time in their history.

Having made 21 League appearances at Bootham Crescent, scoring 3 goals, Liam was told by manager Chris Brass that he would not be offered a new contract and he departed Bootham Crescent and signed for Non-League side Grays Athletic - his seventh club in just over a year.

However, the move didn't work out and after a loan spell at St Albans City (2 appearances, 0 goals), Liam left Grays (6 appearances, 4 goals) and, after a brief stint at Stotfold (2 appearances, 0 goals), he joined Luton's Non-League neighbours Dunstable Town in December 2005. After three appearances and no goals for Dunstable, he joined AFC Wimbledon in January 2006, and after scoring on his debut (10 appearances, 1 goal), he moved to the United States in March 2006, signing for USL First Division side Atlanta Silverbacks, a minor US soccer league compared to the Major Soccer League.

After 22 appearances and 3 goals for Atlanta Silverbacks, Liam returned to England and signed for Southern League side Chesham United at the end of November 2006, where he linked up with former Hatters Dean Brennan and Shane Hill, son of Luton legend Ricky Hill.

However, after just 3 appearances for Chesham United, he left the club and began a trial spell with League Two side Wycombe Wanderers as he looked to make a return to League football.

In December 2006, Liam linked up with hs former Luton Town team mate Stuart Douglas as he signed for Nationwide South outfit Eastleigh, making 5 appearances.

In January 2007, and in a slightly surprising move, Liam returned to Luton Town on a trial basis and appeared as a substitute for the last 25 minutes in a Reserve team match at Leyton Orient.

However, Reserve team manager Marvin Johnson later confirmed that Liam had simply been training with the Hatters to keep fit and, with Luton's Youth team playing in the FA Youth Cup the following day, the Hatters were short of players and so Liam helped out by making up the numbers for the clash at Brisbane Road. There was, apparantly, no chance of Liam ever returning to Kenilworth Road on a permanent basis and he continued to turn out for Eastleigh in the Nationwide South.

After leaving Eastleigh, Liam had a brief stint with Hyde United at the beginning of the 2007-08 season, before signing for UniBond Division One North club FC United of Manchester - his 16th club by the age of 28! However, he only remained with the club for a month before leaving to join Luton's neighbours Barton Rovers, where he linked up with ex-Hatters Tony Thorpe and Scott Oakes. Liam commuted to play for Barton from Manchester, where he was based studying physiotherapy at the University of Salford.