Celtic head to McDiarmid Park on Wednesday night with one eye on the weekend, no matter how much Martin O’Neill tries to play that down.
The Hoops face a St Johnstone side who have won both of their home Premiership matches this season, beating Kilmarnock and Hibernian, and they will be looking to make it three from three when the champions arrive in Perth.
Celtic, meanwhile, have a 100 per cent record and will be looking to maintain their perfect start as they bid to retain the league title for a sixth consecutive season.
There is likely to be some rotation from O’Neill, particularly with Yang Hyun-jun away on international duty and a huge trip to Ibrox waiting at the weekend.
Kasper Høgh and Kieran Tierney were both back in training on Tuesday ahead of the game, but whether either player is thrown straight back into the starting XI remains to be seen.

In goal, Viljami Sinisalo should keep his place. There is little need to rush Sam Johnstone into the side after his arrival, with the Finnish international having done enough to retain the shirt for now.
The back four is also likely to remain unchanged, with Colby Donovan, Cameron Carter-Vickers, Auston Trusty and Liam Scales expected to line up in front of Sinisalo.
There could be a change in midfield, however, with Alex Oxlade-Chamberlain pushing for a start.
The former Liverpool and Arsenal midfielder has shown in recent weeks that he can control games and could come into the side to give skipper Callum McGregor a breather.
Mika Baur and Benji Nygren could retain their places alongside him, with O’Neill having plenty of options in the middle of the park.
Up front, Camilo Duran could move across to the right wing.
Shim Mheuka is another candidate to start through the middle after he thought he had scored his first Celtic goal against St Mirren on Saturday, only for VAR to rule it out for offside.
On the left, Sebastian Tounekti could get the nod. The Norway international has generally been the player O’Neill has turned to from the bench when Yang has needed replacing.
Høgh and Tierney could then be introduced from the bench if they make the matchday squad, giving both players valuable minutes ahead of Sunday’s trip to Ibrox.
With a Europa League opener sandwiched between the two derbies, Celtic are facing a hectic run of four games in the space of two weeks.
O’Neill may insist Wednesday is all that matters, but some careful squad management could be crucial as Celtic prepare for back-to-back derbies with Europe in between.
Predicted Celtic XI:
Viljami Sinisalo
Colby Donovan
Cameron Carter-Vickers
Auston Trusty
Liam Scales
Alex Oxlade-Chamberlain
Mika Baur
Benji Nygren
Camilo Duran
Shim Mheuka
Sebastian Tounekti



