Celtic midfielder Ki Sung-yueng will miss the remainder of the SPL season with a hamstring injury.
The South Korea international limped out of Sunday's 3-0 win against Motherwell after picking up the problem in the first half.
The SPL champions said the 23-year-old will be sidelined for "four or five" weeks.
He misses Sunday's Old Firm derby against Rangers at Parkhead and the final three games of Celtic's title-winning campaign.
Meanwhile, teenage Czech midfielder Filip Twardzik has been ruled out for a fortnight with a foot injury.
The 19-year-old, who has made three substitute appearances for the Bhoys this season, was injured in Monday's 8-0 victory against Queen of the South in the SFA Youth Cup final.