Arsenal fortitude key to success

London - Arsene Wenger believes his players' mental strength will determine whether Arsenal can finish the season on a high.

Wenger's side will attempt to tighten their grip on third place in the Premier League when West Ham visit the Emirates Stadium on Saturday.

That London derby comes five days after the Gunners recorded a memorable FA Cup victory at Manchester United to set up a Wembley semi-final against Reading or Bradford.