First off, to get performance out of an MC he needs to be involved.

Try him on left, red arrow, blue arrow, no arrow, on right red, blue, no.

If he's a player that comes with a new team or he's a Nordgen I tend not to alter the balance of his attributes until I've found where he can play....or not.

Unfortunately there are so many other things I could suggest to try but its impossible to focus on possible solutions without knowing if he gets lots of cards, fouls, mistakes, attributes, guys next to him or if the tactics just mean the game is passing him by. (I'm not asking you to tell me btw - got enough to do >.< )

Some guys you can work with others are just flops. Some higher value young guys are only good for their value - sell them and you can get a few players for that cash.

PS. part of my fun in this game is trying these things - unfortunately it can be a waste of time for others.