Brazilian midfielder Diego looks to be on his way out at Wolfsburg after confirming he has received a "concrete offer" from Atletico Madrid.
The 28-year-old – who spent the 2011-12 campaign on loan at Atletico – has enjoyed a terrific season in the Bundesliga, scoring 10 goals in 32 appearances.
But a return to Spain could be on the cards after Diego, who is contracted at Wolfsburg for another season, revealed that Atletico Madrid were pursuing him.
"Atletico wants me and I have been given a concrete offer," Diego said following Saturday's season-ending 2-2 draw with Eintracht Frankfurt.
"We must now speak with Wolfsburg about what is best for me and the club. I have always been satisfied in Wolfsburg and respect that I still have a year left on my contract.
"But that is precisely the situation that we need to talk about."
Wolfsburg manager Dieter Hecking said he was not surprised that other clubs were interested in signing Diego, but raised doubts on whether their valuation for the Brazilian could be met.
"If his desire to go is really so great, then we need to talk with Diego," Hecking said.
"We have to find arguments to persuade him to stay. However, I cannot imagine that there is a club that will pay enough money for him.
"If you saw him play against Frankfurt, it is clear that clubs come and make offers. We will listen to everything and talk to him but I do not think we will do business unless an offer comes in that is so good that we cannot refuse it."
Meanwhile, Atletico loanee Thibaut Courtois has stressed his desire to remain in the Spanish capital rather than return to Premier League giants Chelsea.
The Belgian goalkeeper, who is just 21, has starred in his two seasons on loan in Spain, helping his side to success and raising his profile significantly in the process.
And with Petr Cech looking secure as Chelsea's first-choice keeper, Courtois would prefer to stay at Atletico and play, rather than warm the bench at Stamford Bridge.
"I want to stay. I'd rather play in La Liga than be a substitute in the Premier League," Courtois said.
"There's a World Cup and I want to go. Here I will be able to play in the Champions League and there's no better place to play than here. At Atletico I have progressed a lot."