Tyton, as fantastic of an asset Carrick is, his lack of involvement in the earlier part of the season wasn't what cost us a shot at the title, there were a few factors, but the main one was simply our woeful chances to goals ratio. If we had of been destroyed in midfield week in week out, getting beat, I'd see what you mean, but it wasn't the case. We've battered so many teams this season in every department, bar the most crucial one; the scoreline, and I don't think Carrick would've had much of a helping hand in that aspect, unless he would've made a monstrous improvement of his 1.5 goals per season, which I somehow doubt. If anything, I'd say the delay in dropping Rooney (which I'll admit I wasn't all for unlike 99% of fans) was arguably a bigger factor than not playing Carrick, as was not playing Mkhitaryan for so long possibly, but hey, that's still hypothetical. But the reason I feel that those are arguably bigger factors is because I think we're better in a 4-2-3-1. I feel 4-2-3-1 with Mata, Mkhi & Martial behind Ibra is better than 4-3-3 with Carrick and Herrera both sitting (Herrera's capable of doing that destroyer like role by himself as he's proved), at least in majority of games. Much more fluid, much more understanding, Ibra seems a lot happier with a natural #10 playing off him, creates more space and increases our chances of scoring goals, which is definitely what we need.
All in all, we've got nobody to blame but ourselves in terms of not being in with a shout of the title in February. We've been our own worst enemies this season. I keep thinking about all the silly points lost; keepers going home with blisters on their hands, that late Giroud goal when we should've had the game already wrapped up, etc. But it is what it is. At least we're still fighting in all competitions, so our season is still very much alive, even if the title is out of reach.