That could pave the way for starts for Fraizer Campbell and James Tomkins, who replaced Walcott and Richards on Monday.
There is likely to be a place in the starting line-up for Walcott's fellow Gunner Kieran Gibbs.
The defender says he has now banished memories of his mistake in the Champions League semi-final last month when he gifted Manchester United the first goal. Gibbs said: "I felt disappointed after that but I'm trying to forget about it now."
Pearce added: "If you're going to go under every time you give the ball away or concede a goal, you are not going to get to the top."
Chelsea's Michael Mancienne serves a one-game ban after he was sent off against Finland.