I think his defending 1 on 1 is actually quite decent, problem is that he hates to give the ball away and sometimes overcomplicates things because of that, trying to work himself out of trouble.
His style of going forward also requires a quality passing from teammates, too many times in 1st half he was overlapping, yet pass was usually not good enough.
He will get plenty of games upcoming season... but it will be Neville who will start as RB at Ewood Park, especially now, when Fellaini is looking much, much better than we could even hope.