Schalke are hoping the return of Ghana's Kevin-Prince Boateng will add some midfield steel for Tuesday's Champions League showdown at home to Chelsea.

The 26-year-old Black Stars midfielder has missed the last two weeks with a knee injury and the Royal Blues are hoping Boateng will reinforce their side against Jose Mourinho's Chelsea star-studded attack.

Schalke are top of Group E after beating both Steaua Bucharest and FC Basel, but second-placed Chelsea arrive in Gelsenkirchen gunning for top spot having beaten Bucharest 4-0 after suffering a shock 2-1 home defeat to Basel in their opening game.

Chelsea will provide Schalke with their biggest test thus far and the Gelsenkirchen-based outfit welcome Boateng back after labouring to a 3-2 win at Bundesliga bottom side Eintracht Braunschweig on Saturday.

"He is an exceptional player with enormous quality and tremendous leadership qualities," said Schalke team manager Horst Heldt.

"Chelsea are the top favourites to win the group and they have a very strong squad. They have numerous possibilities, so we need to step up."

Boateng has made his mark since joining Schalke from AC Milan in late August with three goals in five league games and scored in their 3-0 Champions League win against Bucharest.

"He's an incredible player who spreads fear in the enemy," said Schalke defender Denis Aogo.

As well as Boateng, Schalke are also set to welcome back USA midfielder Jermaine Jones, after a knee injury, and Germany goalkeeper Timo Hildebrand, who had a back problem.

"With them back, we have more options," said Schalke coach Jens Keller.

"We'll take some confidence from our results in the last few weeks, of course we want to win the game, but we'd be able to live with a draw."

Schalke are missing star striker Klaas-Jan Huntelaar, who has a medial knee injury, and winger Jefferson Farfan, who has a torn hamstring.

There was another injury setback for Schalke on Monday when it emerged defensive midfielder Marco Hoeger, 24, has torn the cruciate ligament in his right knee and is set to miss at least the next six months.