Erm, what? You do understand that to get 40 games there he would play 2 out of every 3 games they play? There is absolutely no way he would get a game in their central midfield, not now, nor ever, and he would be an absoute liability if you put him in their front trio because he's nowhere near good enough on the ball to succeed in their formation.
Do you rate Affelay above Milner? I don't, add that to the fact Milner is more versatile I would think he would get more games in the Barca side than Affelay will. Lets see how many games Affelay gets next season.