LEFT BACK
Mikael Silvestre
4 games in this position (7%)
Filled in when all the others were injured, which says it all really. Too old, too far gone, and best well out of Arsenal. Actually he did have a couple of good games this year, but not at left back.
LEFT CENTRE BACK
Mikael Silvestre
9 games in this position (15%)
Filled in when Vermaelen was out. A couple of good games, in the sense that he really gave his all. But to be honest, his all is not good enough any more. Nobody expects him to be at the club next season, and most would say good riddance.
RIGHT CENTRE BACK
Mikael Silvestre
4 games (6%)
Hard to work out the percentages, because Silvestre played a lot of games in various positions. I think, from looking at the stats and racking my brain, that he played 4 times in this position. Not a good position for him because he's left footed and Wenger himself said he didn't really want to play two left footed players at Centre Back together. But inevitable given the amount of injuries we had. His performances were what you would expect from a player who is past it, and on the wrong foot.
But Campbell clearly isn't fit enough to play every week as he had to do late in the season, and Silvestre and Traore have basically been rubbish this season.