Gary Megson fears the fact that Denilson's trial at Bolton has become public knowledge will alert other clubs.
The 31-year-old Brazilian, who at one time was the most expensive footballer in history, is training with The Totters as he is currently a free agent after leaving Palmeiras.
He is now hoping to seal a move back to Europe and Bolton have taken the chance to have a look at him, although Megson feels rival clubs will now be circling ready to make a move.
"Denilson and his people are using it (the trial) as well because it somehow managed to get on Sky television at the exact time he was arriving into the country," Megson said.
"But that's not a problem because Denilson is over here to try and get himself a contract at a football club. And at the moment he's at our club.
"Guys like Denilson don't go on trial because we all know the quality that he's got.
"He's obviously found himself in a position where his contract has finished and he can sign for anybody.
"He's using that, and it's no problem at all.
"He won the World Cup in 2002 and he was part of a fantastic team but it's about the here and now.
"The trial is about us looking at him and him trying to get a contract somewhere."
Megson is also looking to bolster his defence and is in talks with Zenit St Petersburg defender Sebastien Puygrenier and West Ham's Calum Davenport, although he admits he may not push ahead with both deals.
"We've got an agreement with West Ham but we're also looking at other players in that position," said Megson.
"We've also got another player that we're close to coming to an agreement with, so it's decision time.
"We may get accused of messing somebody about but we've got to do what's right for the football club.
"It still may happen that Calum joins Bolton but we'll need another 24 hours before we decide what we're going to do."