Wigan Athletic boss Roberto Martinez has warned Tottenham star Gareth Bale against a move to Spain.
Bale is a target for Barcelona and Real Madrid.
"A real compliment for him is people are talking about him signing for Real Madrid and Barcelona," said Martinez.
"Only a handful of players around the world carry that status and he is one.
"Look at his two performances for Wales against Scotland and Croatia and you could see he was a step ahead of the other 21 players on the pitch. That is quite a statement.
"But it's hard to tell whether a move to Spain would help him improve. Sometimes going to a club we consider as bigger will be healthy. But if you take on a lesser role instead of being the main man it doesn't work.
"It's different if you are one of five or six key men, because maybe the team won't play to your strengths. Certain players enjoy that responsibility of being the main man, and it can be difficult to have the same impact in a team that has three or four other world-class stars.
"Gareth is in a top team, and the way they rely on him is bringing the best out of him."