Personally, I think it makes sense to keep Harris. He's obviously got his limitations at this level, but he's also a workhorse who's not had a lot of good service this year and has played another huge amount of minutes, which has definitely had an impact on his confidence.
Now that we've survived it's unlikely that we're going to be able to upgrade the whole squad over the summer with a play-off push in mind. We need to recruit sensibly to upgrade the priority areas, but also ensure that there's enough depth in the squad. Harris would probably be viewed much more favourably his season if we'd had alternative options to play differently depending on the opposition and rotate him out more.
I also think Rowett's comments have been telling - our lack of athleticism and ability to press for long periods has meant Harris has often been chasing by himself, and we've not really won the ball in high areas very much. His harrying and pressing are a big part of his game and he's not been able to be as effective at that this season, and he's ended up increasingly isolated as a result.
He's one that I think could look a lot better if Rowett can add that athleticism he talks about, particularly in central areas, and is still worthy of a squad place next year if Rowett thinks we can play a better press more consistently.