[2] Born in Clacton-on-Sea, Westlake progressed through the youth ranks at Ipswich Town, at the club's reserves and academy.
"[5] Westlake made his debut for Ipswich Town, coming on as a substitute in a 1–0 home defeat to Gillingham on 26 October 2002.
[6] Having spent months at the club's reserves, it wasn't until on 15 March 2003 when he made his return to the first team, coming on as a 72nd-minute substitute, in a 1–0 win against Sheffield Wednesday.
[16] Westlake played in both legs of the Division One Play–Offs against West Ham United, as Ipswich Town lost 2–1 on aggregate.
[17] At the end of the 2003–04 season, he made a further 43 appearances for the club and also scored 7 goals,[18] For his performance, Westlake was awarded Ipswich Town Player of the Year.
[22] In his 50th appearance for Ipswich Town against Derby County, Westlake set up the club's first goal of the game, in a 3–2 loss.
[37] He didn't make a return to the first team until on 10 December 2005 against Queens Park Rangers, coming on as a second-half substitute, in a 2–2 draw.
By the time Westlake departed Ipswich Town for Leeds United, he made a total of 125 appearances for the club, scoring 17 goals.
[50] On 3 March 2008, it was revealed that Westlake had agreed an initial one-month loan deal at League One play-off rivals Brighton & Hove Albion.
[51] Westlake made his Brighton & Hove Albion debut, starting the whole game, in a 4–2 win against Gillingham on 4 March 2008.
[53] While on the sidelines, it was announced on 3 April 2008 that Westlake, Leeds United and Brighton & Hove Albion agreed that the player would remain on loan at the Withdean for the remainder of the 2007–08 season.
[59] On 24 October 2008, Westlake joined League One side Cheltenham Town on an initial three-month loan deal.
[65] Westlake also scored on the day of his permanent debut for Cheltenham during the 2–2 home draw with Brighton & Hove Albion.
[66] With Cheltenham Town suffering from financial difficulties, Westlake joined League One side Oldham Athletic on loan for the remainder of the 2008–09 season on 19 March 2009.
[69][70] On 15 July 2009, Westlake signed a two-year contract with recently promoted League One side Wycombe Wanderers.
[71] After missing the opening game of the season due to a hamstring injury, he made his debut for the club, starting a match and played 62 minutes before being substituted, in a 1–0 loss against Leeds United on 15 August 2009.
[84] After being released by Montreal Impact following the introduction of a "six foreign players" rule, Westlake returned to Suffolk before signing for Needham Market eighteen months later in June 2013.
[85] Westlake made his Needham Market debut, starting the match and scoring his first goal from a free kick, in a 3–0 win against Romford.
[90] In the 2014–15 season, Westlake returned from injury and continued a first team regular for the side, as well, as producing his goal scoring form.
[92] Westlake helped Needham Market win the Ryman Division One North title following a 5-0 victory over Chatham Town.