Well it depends on your point of view. You could say that because they're playing for a team in the Premier League then they're PL players. But we know that isn't true.
Bradford's run to the League Cup final saw them beat 3 Premier League sides (Wigan, Arsenal and Villa), a Championship side (Watford) and a League One side (Notts County). Their whole team played well in every game, so did that mean that their squad was full of Premier League quality players? Or was it that they were in fact League 2 quality, but showed a lot of commitment and effort?
Quinn was a handy player to have and he did his best when called upon, but no way is he talented enough to be a regular, consistently quality Premier League midfielder. Had Diame been fit, he (Quinn) would have spent most of the season on the bench being used as an impact player. Similarly, when it became public knowledge that his contract was about to expire, he ended up going to a Championship club. As did McShane and Rosenior and I assume the same will happen to Bruce Jnr.
It's not to say they're bad players, because they aren't, but their ability levels aren't enough to be classed as Premier League quality. We were blighted with injuries and suspensions last season so we had to plug the gaps with players like Meyler, Bruce, Quinn and McShane. If they were PL quality players, we wouldn't have struggled so much, but because we had to rely on Championship level players, that's where we ended up. Fair play to them for stepping up to the plate and having a go at keeping us up, but even they knew their own limits and it's probably one of the reasons why they didn't turn down those Championship contract offers to wait for PL interest.