However, the Packers won't know until next week whether he will be available for their post-bye game against the Chicago Bears on Nov. 9.
"Not sure about a timetable yet," the source said.
The injury was diagnosed as a sprain. Lang was injured at the end of the first series in Sunday's 44-23 loss at the New Orleans Saints. He appeared to land awkwardly while blocking an extra point. He played just five snaps on offense and the lone special teams snap.
He left the Superdome in a walking boot and did not speak to reporters. However, he tweeted a message earlier this week.
Optimistic about the ankle injury and thankful for the bye! Thanks for the kind words.— TJ Lang (@TJLang70) October 27, 2014
Tretter, who was slated to be the starting center this season, is eligible to come off the injured reserve/designated to return list this week. Given how well rookie Corey Linsley has played in Tretter's spot, it's unlikely the Packers will go back to Tretter at center.
The Packers are monitoring several other injuries during their bye week. They were without three defensive starters -- safety Morgan Burnett (calf), cornerback Sam Shields (knee) and defensive end Datone Jones (ankle) -- against the Saints.