McKenzie is a harsh one - although he looked out of his depth at right-back, he did OK at centre-back and a level down might have aided his development.
He never looked a world-beater at centre-back, but we forget there were times under Adkins he played centre-back alongside Ridgewell and still did well!
Bowler - you can see if an experienced manager took him by the scruff of the neck, pointed out his flaws, he could develop into a good player.
As it is, he's spent a season constantly beating everyone for pace and then smashing his crosses into row Z and nobody has done a thing about it.
He's going back to Everton the exact same player he was when he arrived - knows he's got natural talent, but is blind to what let's him down (and those things are huge if you want to make it as a footballer).
MacDonald - Considering he's had injury and health problems ever since he arrived, we've never had the opportunity to see the best of him, but he looks to (hopefully) be over his injury troubles and has thankfully overcome his battle with cancer which will have made him a stronger person because of it. I'd be happy to see him sign a new contract and hope he does - to say he's barely played any games in the last 2 years, he didn't look any worse than anyone else in the side (and I know that doesn't mean much considering how poor we've been), and when you put it into perspective with what he has been through...