Just discussing this over at A-M. I like Jagielka, I think he's a good Premier League defender, but I don't think he's quite good enough for us, or more importantly, the type of centreback that we need.
He's similar to Vermaelen, in that he reads the game well, is very mobile for a centreback and comfortable on the ball, but I think Vermalen is superior in each of those things. I also think Vermaelen is stronger and much more aggressive/dominant in the air.
Cahill might not read the game quite as well, but he's a lot stronger in the tackle, and more aggressive/dominant in the air - and I think between the two, Cahill gives us a bit more of what we need.
