Sunderland striker Martyn Waghorn has escaped serious injury after being stretchered off the pitch during the pre-season friendly against Munster earlier this week.
Waghorn scored twice before suffering a knee injury although scans have shown the problem is not serious.
Assistant boss Eric Black has confirmed that the forward will miss the game against Darlington but will be fit enough to travel to Portugal and could feature in the match against Brighton in Albufeira next Wednesday.
"Martyn's doing very well," said Black. "We're delighted with his progress after what looked like a nasty one against Munster.
"Thankfully we've checked the scans and he's fine. He has a bruised patella in his knee and he also hurt his shoulder when he fell. We're hopeful Martyn will be able to rejoin the group on Monday or Tuesday.
Meanwhile, Scotland manager Craig Levein is disappointed to learn of Craig Gordon's latest injury woe.
The former Hearts shot-stopper will miss the start of the campaign after fracturing a bone in his arm when falling awkwardly in training.
Levein said: "It's obviously very disappointing to lose a goalkeeper of Craig's calibre for such a significant part of the campaign.
"I'm as disappointed for the player himself as I am for the country because I know how hard he has worked to overcome a series of injuries.
"Craig has been an exceptional goalkeeper for Scotland - a talisman in fact - and I think after getting a metal plate inserted in his arm last season, he was getting back to his best form for Sunderland.
"He also made some outstanding saves in my first match against the Czech Republic."