McDonald may return
St Johnstone boss Tommy Wright is hopeful of welcoming back Gary McDonald for Saturday's visit of Inverness - but the Perth boss has been told Steven Anderson might be ruled out for eight weeks.
The central defender dislocated his thumb in last weekend's 1-1 draw with Partick and was forced to undergo surgery to repair ligament damage to the digit.
McDonald, however, has trained again after shaking off the hamstring strain that kept him out of the Thistle clash, leaving leg-break victim David Robertson as the only other confirmed absentee for the match with Terry Butchers' Scottish Premiership table-toppers.
St Johnstone's Alan Mannus will face up to Northern Ireland mate Billy McKay at McDiarmid - but the keeper admits he is surprised to see the striker lining up for Inverness at all.
McKay struck 27 times for the Highlanders last term and will hope to push this season's nine-goal tally into double figures when table-topping Caley Thistle head south to Perth.
But international colleague Mannus admits he expected to see the Northampton frontman return south in the summer after his spectacular exploits in front of goal.
He said: "I'm quite friendly with Billy whenever we meet up with Northern Ireland. We like to have a muck around and a laugh playing darts.
"He's a good guy but I'm surprised he's not had any offers from bigger clubs down south given the amount of goals he scores.
"Billy's one those strikers that is going to guarantee you 20-odd goals a season.
"He scored 27 last year with a club like Inverness, where you don't get as many chances as you would with a bigger side like Celtic, so I thought someone from the Championship might have taken a chance on him."
Inverness will be without James Vincent after the midfielder was forced out of last week's win over Hibernian through injury and scans have shown some damage to the knee.
Vincent will see a specialist to ascertain how long he is likely to be sidelined, with boss Terry Butcher otherwise boasting a fully-fit squad.