The duo struggled to make an impact at the Westerstadion last season.
Allofs told Bild: “He (Vranjes) did not have the best of seasons this term.
“In the end it was a bad campaign. We want to make our squad stronger with more strength in depth, though it will be a tough time for Vranjes if he stays on.”
He added on Tosic: “We have to wait and see what options both players are going to have this summer.”