Should Arsenal's bid for Fellaini affect Chelsea's decision making?

According to the Times, Arsenal have become the first team to activate Marouane Fellaini's buyout clause, despite all the chat about him going to Manchester United or Chelsea. The cost? £22 million.All very well and good, but what does this mean to Chelsea?

We're all familiar with the idea that matches against one's rivals matter more than the others. The reason is that should one side win, the other side must therefore lose, so a win not only gains you points but also denies the opposition points as well. A similar logic might be applied to transfer rumours -- if Arsenal sign Fellaini, they get better while also preventing Chelsea or United from getting better.

I suspect that that line of thinking is a little misguided in this case. If Arsenal spend £22 million on the Belgian, it's true that they then have him and Chelsea do not -- but then Arsenal don't have that £22 million (plus wages) anymore. For top end talents (Edinson Cavani, for example), denying your opponents access to those players makes sense, because they're in such short supply that they're almost impossible to replace.

Midfielders like Fellaini, especially when one considers the style of play he'd have to adopt to be successful at Chelsea, are much more abundant. Despite Fellaini being unique in many ways, as a pivot player he's essentially fungible (Gunners fans agree; see The Short Fuse). Arsenal converting cash into Fellaini simply means that they can't convert that cash into some other Fellaini equivalent.

It's not necessary to block off the Gunners here. If Michael Emenalo and Jose Mourinho think that Fellaini must end up at Chelsea for next season, that would certainly be reason to pursue him. But Arsenal's interest in acquiring him is insufficient motivation for the Blues to go in hard to try to lure him to Stamford Bridge. He's a good player, and will almost certainly make them better, but if they're committed to spending £22 million plus wages on getting better, we can't possibly block every move they might make.

Is Fellaini a fit for Chelsea right now? It depends on what you think of his play in the centre (and the possibility of him playing in a strikerless formation, which would be cool). If he is a fit, the team should pursue him. If not, they shouldn't. For players like this, interest from other teams shouldn't matter at all.