FWIW, I think he'll stay, I also think, if he plays in the same position as he has for us that he could do a good job too. I also think that he's been carrying an injury since around Christmas/New Year when he was out with his knee because he's generally had 60 minutes a game since then.
I think he's been a vital part of the side. When you watch us, he's always available for the ball and picks it up in various areas making him a nightmare to mark. I don't think pace is a necessity in that role and although he does sometimes tries to do too much, I think the amount of assists and general involvement in our attacking play outweighs the negatives.
That said, I can also see a scenario where CW might say he's not guaranteed a starting place and will have to compete with Samir, Jay and possibly others too, then he might consider a move and I'm sure there would be plenty of suitors.
I think the OP has forgotten that in the early part of the season and probably up to around January Duffy was MOTM or nearly for a considerable number of games. I agree that he has not been as prominent over the last 3 months or so and has generally only lasted for 60 minutes or so. It may be as is suggested he has been carrying a bit of an injury. But you also have to look at the amount of work he gets through. He always seems to be available to receive the ball all over the pitch. There is such a thing as cumulative fatigue which can develop over the season and it is hardly surprising if he got this towards the end. I think he can definitely do the same job next season and should be given the chance. The only reason he might move on is if a L1 club comes in with a good offer and he himself decides he wants to go.
Really hope Carruthers stays. Think he could be a great player for us.