I think people think too much about a strict starting XI, we should be looking at increasing our options within the squad rather than trying to fill specific roles.
Left Back - Kolarov is no slouch but I think we may need a bit of genuine pace at full back especially in the Champions League next season. I know he's not everyone's favourite but with Gael Clichy's contract at Arsenal running out this summer I think he'd be the perfect addition. He's not the best defensively but who is at Arsenal? With Mancini's defensive coaching he would improve dramatically like Micah and Zabba. I still think Kolarov deserves his chance though after a good pre-season inside him.
Central Midfield - There's nothing wrong with our midfield at present (De Jong, Yaya, Milner, Barry and Silva) but I do think we need another ball playing midfielder, one who can keep possession and create chances in a similar fashion to Silva. Modric would be an absolute star here but whether we could get him or not who knows.
Winger - AJ is absolute class when he's on form but we do need another one and one with explosive pace. If it was me I would throw all our money at Arjen Robben, he's only 27 and has Premiership, Champions League and International experience coming out of his arse. He would give us that devastating edge when games are tight and compact. He could be the difference between finishing 3rd and winning the league. Sanchez looks a decent player but at £35m no fucking chance, he losses possession way too frequently and to me is just a "youtube" Robinho mark II player