The Swedish international has missed the Rossoneri's past couple of games including the 2-2 draw with Barcelona in the Champions League as well as the 3-1 defeat to Napoli in the Serie A on Saturday.
But according to Italian daily La Gazzetta dello Sport, the 29-year-old has returned to Milan on Monday evening after spending the past few days in his native country recovering from the injury.
Milan coach Massimiliano Allegri is believed to be reluctant to throw him straight into the starting line-up on Saturday but the striker could make an appearance from the bench.
But he likely to be ready to start in his side's upcoming Champions League home game against Viktoria Plzen on September 28.
Another player making his return to the Milan squad is Filippo Inzaghi, who could be included in the match squad to face Udinese in midweek.
The veteran striker has been out of action for 10 months due to a knee injury, but impressed in training on Monday and could make the bench for Wednesday's game at San Siro.