Way I see it, there's three reasonable reasons for selling a player:
1) You're desperate for the money, and can't risk losing him for nowt.
2) The money is as much as you're ever going to get for the player i.e. you're selling a peak value, and the money would be better invested into some other playing assets, or
3) If you don't sell the player, he's going to get so pissed offer that it'll either ruin dressing room morale or, worse, dissuade future signings from joining as you'll get a reputation for standing in the way of careers
Well from all reports, with our current owners, we've no need to sell. And we've still got him under contract for two more years so he can't walk for a while.
I'd be really surprised, based on what I've seen, if McNally didn't get better with more experience. I don't think he's anywhere near his peak value yet.
And he's a young kid with only 30-odd English games under his belt. I would hope that he would respond OK to us saying 'Not yet - we need you to stay for another year'. Plus, while Burnley are undoubtedly a bigger club than us.....they're not exactly a footballer's dream, once in a lifetime opportunity. If Spurs were really in for him, then that might be harder to turn down for Reason #3.
So I don't think I would be selling McNally unless Burnley offer silly money. Like breaking our record transfer fee received-type money.