Stephen Warnock fears Aston Villa team-mate James Milner may leave the club over the summer if 'the price is right'.
Milner has enjoyed an impressive season for Villa and his performances were rewarded with the PFA Young Player of the Year award.
His form for Martin O'Neill's side has seen him linked to several of Villa's Premier League rivals and Manchester City have already had a £20million offer turned down.
Chelsea and Manchester United are also rumoured to be keeping tabs on the midfielder, who Warnock hopes will stay in the Midlands.
However, the left-back is also aware that a significantly improved offer could persuade Villa to sell England's World Cup hopeful.
Warnock, speaking after England's 3-1 win over Mexico at Wembley, said: "I don't think the amount of attention James is getting is a surprise.
"I think everyone knows his ability and what he's about and what he's put in on the pitch at Villa this year.
"I think everyone knew his reputation before he even joined Villa, what he could be and what potential he had about him, and he's done very well.
"He can operate anywhere, he's very comfortable anywhere he plays and he's a quality player.
"I don't think the speculation (about his future) has affected him at all. You only have to see the way he's been in training and the way he played the other night (against Mexico). Nothing bothers him really, he just gets on with it."
Warnock added: "Of course, we want him at Villa next season, but I think, if the price is right, it's very difficult for a club to turn it down.
"From his point of view, if there's a chance to play at a higher level, then it's something that I'm sure he'll be open to."