By Chris Harris

Arsène Wenger admits that Theo Walcott may have played his way into the starting line-up for Tuesday's visit to Barcelona - but the Arsenal manager wants game-changers on the bench too.

Walcott did exactly that when he entered the fray after 66 minutes of Wednesday's Champions League Quarter-Final first leg at Emirates Stadium. The 21-year-old scored Arsenal's first, was involved in the build-up to their equaliser and caused havoc with his pace on the right flank.

Wenger now has to decide whether to play Walcott from the start in the Nou Camp as Arsenal chase the win - or high-scoring draw - they need to reach the Semi-Finals. Speaking before the weekend, the manager admitted he faced a "difficult" choice.

"You have big players on the bench," said Wenger. "When they come on you don't forget they have qualities to make an impact.

"It is always difficult to measure - is the impact is down to the quality of the player and the history of the game or is it just down to the quality of the player? It is very difficult to say.

"I must say I am very, very happy that Theo had such an impact on the game. But he played three days before at Birmingham and had not the same impact on the game and he started. Every game is different.

"Theo has a chance to start the game [on Tuesday] but he can as well come on again and make a difference. If it is 0-0 with 20 minutes to go, we will need players who can make a difference."

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 3 Apr 2010