Schalke are thought to have triggered a clause to sign Franco Di Santo, with current club Werder Bremen confirming the forward's exit.
Werder Bremen have confirmed Franco Di Santo has left the club with immediate effect, with Bundesliga rivals Schalke widely reported to have completed a deal for the forward.
Di Santo moved to Bremen from Wigan Athletic ahead of the 2013-14 season and has scored 17 goals in 49 league appearances for the club.
However, the Argentine was taken out of the Bremen squad to face Sevilla in a friendly on Saturday, with his exit from the Weserstadion duly confirmed.
"Franco Di Santo leaves Werder with immediate effect after a clause was activated in his contract," read a statement on Bremen's official website.
"Consequently, he will no longer train with the team and will be unavailable for selection for this afternoon's game against Sevilla."