Republic of Ireland midfielder Wes Hoolahan is an injury concern for the Euro 2016 Group D qualifier against Scotland at Celtic Park on 14 November.
The Norwich City player was helped off the pitch during the second half of his side's 1-0 Championship defeat by Fulham at the weekend.
Initial reports from Canaries manager Neil Adams are not promising in terms of Hoolahan making a speedy recovery.
Hoolahan featured in the Republic's recent wins over Gibraltar and Germany.
"He's in a protective boot, obviously we'll have to look at him and scan him, but he said straight away that it wasn't a great one," explained Adams.
"Fingers crossed o nit, but it doesn't look good at the minute."
The 32-year-old started and scored in the 7-0 thumping of Gibraltar and then came on as a substitute against Germany, providing the cross that led to John O'Shea's late equaliser in the 1-1 draw in Gelsenkirchen.
Martin O'Neill's side lie second in their group after three rounds of fixtures, level on points with leaders Poland, and three points ahead of world champions Germany and Scotland.