Northern Ireland defender Jonny Evans will miss Thursday's crunch Euro 2016 qualifier against Greece, but could yet feature against Finland.
Evans, 27, suffered a hamstring injury at the weekend and has not yet travelled to Belfast.
The West Brom centre-half will make the journey ahead of the Greece clash, where victory will be enough to secure a place at Euro 2016, and should his country still need a result in Helsinki he will be assessed.
"Jonny will join the squad tomorrow with a view to Sunday," manager Michael O'Neill said. "West Brom have been excellent in terms of co-operation on that. We always felt tomorrow night would be too soon but he hasn't ruled out Sunday, neither have we and neither have the club."
O'Neill had been hoping to field Evans alongside Baggies teammates Chris Brunt and Gareth McAuley in his back four, but must now rethink.
Craig Cathcart is the leading candidate and looks certain to start after a promising return to the Premier League with Watford.
O'Neill must also find replacements for suspended trio Conor McLaughlin, Chris Baird and Kyle Lafferty.
Manchester United's Paddy McNair, who can play in defence or midfield, looks certain to come in, with Josh Magennis set to deputise for seven-goal top-scorer Lafferty.
Jamie Ward, absent against Hungary last month with a hamstring problem, will return to share the goal-scoring burden.
O'Neill said: "Obviously the injury to Jonny at the weekend was a blow but one thing I have noticed in those three days, maybe more so than in the past, is that the squad is stronger now than at any time I've been in charge.
"I genuinely believe that we have the players to step in and deal with this game, in terms of dealing with the situation with Jonny not being available, and also with the suspensions we have as well.''