The club confirmed last week that the 35-year-old Swede was returning to Old Trafford on a one-year contract.
The former Sweden international had been released after his prolific first season at United was brought to an end by a knee ligament injury.
After the Premier League win against Leicester on Saturday, the Portuguese gaffer told BT Sport, “He will be back in January.
“When the market is open and people are spending money, we don’t.
“But we get a player who was fundamental for us last season. He comes to give us extra quality in the second half of the season.”
Source: Daily News online