Wolfsburg coach Felix Magath has asked for Diego's future to be sorted out one way or the other by the end of July.
The Brazilian attacking midfielder spent last season on loan at Atletico Madrid after falling out with his coach and looks likely to leave the German club in the near future.
And the 58-year-old trainer has confessed that he wants an end to the speculation so he can organise his squad for 2012-13.
“Topics such as [Simon] Kjaer, Diego, or whoever - that must be decided by the end of July," Magath told German reporters.
"Otherwise we will decide that the issue will end and these players will go into the season with us.
"I know that he offers. Probably from Flamengo. For Brazilians, the domestic league is always a stepping stone for the national team.
"By the end of July, we want to have the most important transfers in the bag. That's before our training camp and so it has been discussed with our board,” he confirmed.
Meanwhile, Flamengo sporting director Zinho has once more stated that the South American playmaker has indicated a willingness to move back to his homeland.
"Diego has made it clear that he wants to play with us,” the executive told Bild. "Now everything depends on Wolfsburg.”