Werder Bremen have sought to play down any suggestion that they might be looking to re-sign Diego.
The Bundesliga outfit are in the market for a creative influence after agreeing to sell the highly-rated Mesut Ozil to Real Madrid.
The departure of the German international has sparked speculation as to who will be drafted in to replace him.
It has been rumoured that Brazilian playmaker Diego, who left Bremen for Juventus last summer, could be lured back to Weserstadion.
The Samba star is believed to be growing disillusioned with life in Serie A and may well be tempted by a switch elsewhere.
However, Klaus Allofs believes a deal to bring him back to Bremen would be 'economically impossible'.
"No club likes to lose a player of Mesut Ozil's calibre, there is no doubt about that," Bremen's general manager told the club's official website.
"Him leaving has put us in the same situation as when Diego left for Juventus last summer.
"I understand that many of our supporters would like to see him back, but this is nothing more than wishful thinking.
"Diego enjoyed his time here but he left because he was able to earn more money at Juventus than at our club. This is still the case.
"In addition, Juventus would be looking for a sizeable fee. To re-sign Diego from Juventus is economically impossible for a club like Werder Bremen."
Meanwhile, Bremen's plans for the 2010/11 campaign have received an untimely knock with the news that Naldo is set to be sidelined for some time.
The Brazilian centre-half is nursing a knee injury which may require surgery, meaning he will be missing for the foreseeable future.
"I have hardly been injured throughout my time at Werder," Naldo told Kicker-Sportmagazin.
"I am still hopeful that this injury will soon be gone."