in a series of post-season friendlies for England. But that was to be the Englishman's final season with the Lancashire club. Not long after the departure of manager Mark Hughes to Manchester City, Bentley reiterated his desire to leave. Blackburn placed a valuation of the player at around £18 million. Tottenham Hotspur On 31 July 2008, Tottenham Hotspur announced their signing of Bentley, on a six-year contract, for a £15 million fee, with an additional £2 million conditional on future performance. Reports suggested that £7 million of this fee was payable to Bentley's former employers, Arsenal. Bentley made his competitive debut on 16 August 2008 away at Middlesbrough where Spurs lost 2–1. He scored his first competitive goal for Spurs in the 2008–09 UEFA Cup first round tie against Wisła Kraków on 18 September 2008. He then scored his first league goal for Tottenham against his old club Arsenal with a 43-yard dipping volley in a 4–4 draw on 29 October 2008. This led the British mathematician Tony Mann to ask Marcus du Sautoy to name a symmetry group in honour of David Bentley; the group is labelled Set [C[1], C[2], C[3], C[4]]=[40, 13, 4, 4], with the final two digits corresponding to the result of the match. Bentley's form would suffer at Tottenham, however, and after falling down the pecking order for both club and country, it was reported on 17 June 2009 that he was in talks to move to Aston Villa. Subsequently, it was revealed by Bentley and Aston Villa that this was untrue. The form of Aaron Lennon meant that Bentley was mostly used as a substitute for the start 2009–10 season, although he did score a free kick in Tottenham's 9–1 victory over Wigan Athletic, with the ball then going in off the back of Wigan goalkeeper Chris Kirkland. Loan spells On 12 January 2011, Bentley joined Birmingham City on loan for the remainder of the season. He went straight into the starting eleven for the Second City derby against Aston Villa and was named man of the match. Bentley scored his first goal for Birmingham in a 3–2 win against Coventry City in the fourth round of the 2010–11 FA Cup. Bentley was cup-tied for Birmingham's victory in the 2011 League Cup Final. Described in the Birmingham Mails season review as having "flattered to deceive", he failed to establish himself in the first team,