He was in the starting line-up for the opening game of the season on 5 September 2009 against Harlequins, played at Twickenham as part of the London Double Header [clarification needed].

After treatment on the field for a cut sustained to his nose Simpson continued to play for the remaining 79 minutes, despite feeling sick and dizzy.

This is Simpson's second major injury in less than a year, having been stretchered off in the 26–21 home defeat by Leicester in May 2015 with a medial collateral ligament blow, dashing his hopes of making the World Cup squad.

[5] In September 2021, Saracens announced Simpson would join them on a one-month loan deal from Gloucester to provide additional cover following Ivan van Zyl suspension as well as Ruben de Haas being away on international duty.

In June 2009 Simpson progressed into the England Saxons squad and travelled with Wasps' teammates Dom Waldouck and Danny Cipriani to play in the Churchill Cup in Colorado.

On his debut he completed a solo try and was awarded Man of the Match and appeared twice more during the tournament (in which the Saxons lost the final to Ireland A), coming on as a substitute.

[12] On 22 August 2011 Simpson was named in the 30-man England squad heading to New Zealand for the 2011 Rugby World Cup, the opportunity arising following an injury to Danny Care.

On 18 September 2011, Simpson replaced Ben Youngs in the 66th minute against Georgia in the pool stages of the Rugby World Cup 2011 to win his long anticipated first cap.