From an outsider looking in he seems to have lost a yard of pace (which happens when you get older obviously). He always used to bomb forward and overlap the winger, always providing another option. I don't see that as much, which isolates the attacker. I know injuries have played their part too. I've only saw about 5 of your games though - So you'll all know a lot more than me. It may be that he's told by the manager not to get forward as much, focusing more on his positional sense, or it may be that Baines himself doesn't want to commit too far forward as he himself knows he doesn't have the legs to get back anymore - Not sure.
I remember him taking a cracking free kick and getting 4/5 goals per season with superb free kicks and he took the penalties too. I don't see that as much.
On a side note, when is Coleman back for you? Know he suffered that horrific leg break playing for Republic of Ireland. Recently watched a programme where he spent time with kids with down syndrome, what a true class act. On the pitch, I think he's one of the most consistent full-backs in the league. He destroyed us at the SOL a few years back. Just kept getting forward and putting in great deliveries, yet had the pace/fitness to get back too. What a gem of a player you've got there lads/lasses.
He'll be a huge boost when he's back.