Daizen Maeda and David Turnbull both took part in a Celtic training session on Thursday after picking up injuries during the international break.
Japan striker Maeda was substituted at half-time in last Friday’s friendly against the United States due to a thigh problem and was not fit enough to make the squad for Tuesday’s game against Ecuador.
Turnbull withdrew from the Scottish squad with an ankle injury after initially reporting for duty.
The former Motherwell midfielder and Maeda could face former club Turnbull at Celtic Park on Saturday, but after the two were caught training at Lennoxtown in a video posted on their club’s Twitter account.
There was no sign of forwards Sead Haksabanovic and Giorgos Giakoumakis or centre-backs Cameron Carter-Vickers and Carl Starfelt in the footage.
Giakoumakis was in the Greece squad but a problem with his leg meant he was not considered fit enough to feature in their Nations League matches against Cyprus or Northern Ireland.
Greece coach Gus Poyet has said he does not expect Giakoumakis to be available for the Hoops this Saturday as they look to get back on track after their recent loss to St Mirren.
Haksabanovic was knocked out 32 minutes into Montenegro’s 2-0 Nations League home defeat to Finland on Monday.
Carter-Vickers has pulled out of the USA squad after sitting out during training ahead of the St Mirren game while Starfelt recovers from the knee injury he suffered against Rangers in early September.