Selection dilemmas for Wenger

By 1970's Gooner Arsene Wenger has a decision to make for the Champions League Group H encounter against Sevilla. Does he continue with Gilberto in central defence or does he opt for the returning Senderos. This is a much more difficult decision than it first appears because either selection will have repercussions elsewhere in the formation of the team but also in Wenger's future planning.