Celtic skipper Scott Brown has undergone surgery on an abductor problem during the international break and will be out for four to six weeks, manager Neil Lennon has confirmed.
Ahead of Sunday's Scottish Premier League clash with St Mirren in Paisley, the Hoops boss gave an injury update at the club's Lennoxtown training complex.
He said: "Scott Brown had surgery in the break and so he is looking at a month, four to six weeks.
"Thomas Rogne has a hamstring strain and he will out for two to three weeks. James Forrest (back) is continuing his rehab at the minute.
"Joe Ledley didn't train today, due to a slight groin strain but will hopefully train tomorrow and Adam Matthews (hamstring) will train on Monday.
"Charlie Mulgrew is fine, he had a tight hamstring before the Serbia game and Gordon Strachan didn't take any chances with him obviously, but he came through training (on Friday) okay."
Information from the Press Association was used in this report.