"We've a Uefa Cup bid and that's going to put a strain on us with the amount of games and the size of our squad," James told The Mirror.
"Middlesbrough proved in 2006 you can go so far in the Uefa Cup but unless you win it, it becomes a bit of a fruitless task.
"It's going to be important we keep our players fit to do well in Europe and on the other front to do well in the league. "As we found in the FA Cup last season it is easy to take your eye off your league position," added James.
"Arguably we could have finished fifth, but with the FA Cup we didn't and we ended up eighth."