Germany star Bastian Schweinsteiger returned to light training with Bayern Munich on Thursday, three weeks after injuring his right ankle, but wing Franck Ribery is doubtful for this weekend.Bayern, who are second in the German league, are at Bayer Leverkusen today and are waiting on the fitness of several stars including Ribery.The Frenchman suffered a deadleg injury in France’s 2-1 win over Germany in Bremen on Wednesday when a few fellow Bayern stars also picked up knocks.Defender Holger Badstuber and Jerome Boateng both have back problems while Thomas Mueller has returned from Germany duty with a hamstring problem."Now we have to wait and see how things look after the recovery training,” said Bayern coach Jupp Heynckes.There was some good news for Heynckes as Schweinsteiger, 27, got the green light to start running again at Bayern’s training centre, although it remains unclear when he will be able to play again.Schweinsteiger tore ankle ligaments in the German Cup quarter-final win at Stuttgart on February 8 on just his fourth game back after breaking his collarbone in early November.Bayern host FC Basel in the second-leg of their Champions League Round of 16 clash on March 13 and need to over-turn a 1-0 defeat from the first match in Switzerland.