The Stoke centre-back joined Wolfsburg on loan at the start of the season after falling down the pecking order at the Bet365 Stadium.
He made 45 appearances before leaving the Potters temporarily but he has been unable to find first-team football in Germany.
Wollscheid admitted this week he would happily play for the club's Under-23 side although Wolfsburg have revealed he has now suffered a thigh injury.
However, Ziehl insists he has played a key role in the dressing room as he tries to force through a permanent move away from the Premier League side.
He told Wolfsburger Nachrichten: "Philipp has already been able to address the team with a few words, all of which have been positively received. He wants to not only play with us but also train. This is for him, instead of commuting between the two teams.
"We now have five central defenders in the squad and the competition for places is great."