Wolfsburg playmaker Diego is the second highest earner in the Bundesliga with a salary of 8.2 million euros (US$10.9m) a year, according to a report into the Bundesliga strugglers' huge wage bill.
German news magazine Der Spiegel has revealed Brazil midfielder Diego is the clubs's top earner while fringe players striker Srdjan Lakic and midfielder Christian Traesch each earn nearly three million euros (US$4m) before bonuses.
According to the report, only current Bundesliga leaders Bayern Munich have a larger wage bill and Diego's salary is the league's second highest behind Bayern Munich's France star Franck Ribery, who is reported to earn 10 million euros.
Having spent last season on loan to Atletico Madrid, Diego has scored four goals in 16 league games so far this season.
Despite only narrowly avoiding relegation in 2011 and finishing eighth last season, Wolfsburg's squad of 35 players is one of the biggest in the German league and team manager Klaus Allofs must trim his squad.
His predecessor Felix Magath, who was sacked as team manager and coach by Wolves in October, recruited heavily during his 18 months in charge, signing 26 players.
"It is certainly the case that with one or two players in the past, someone has overshot the target," Allofs admitted having taken over in November with his team now 15th in the league, one above the relegation places.
"We have to do something about that."
With the Bundesliga set to restart this weekend, Wolves, who host Stuttgart on Saturday, have loaned defender Marco Russ to Eintracht Frankfurt and bought Dortmund midfielder Ivan Perisic for a reported fee of around 7.5 million euros (US$10m).