The influential Pawlett sat out the Scottish Cup quarter-final victory over Dumbarton on Saturday but will be in the squad to face Inverness in Glasgow this weekend.
"Peter will be fit," said McInnes. "He hasn't trained with the squad but has done everything the physio has expected of him.
"He should train on Wednesday and, if he comes through pain-free, that will be him. The physios are confident that he'll be good to go. They wouldn't give him back to us if they didn't think he was fit."
Aberdeen's support will outnumber the Inverness fans by a ratio of 4 to 1 and most pundits are tipping the Dons to claim their first silverware for 19 years.
McInnes is confident that his players can cope with the pressure and go on to deliver success at Celtic Park on Sunday.
"We're going to play the game, not the occasion, as we have done all season," he told the Scotsman. "Whether we're overwhelming favourites like we were on Saturday against Dumbarton, or underdogs against Celtic at Parkhead as we were in the Scottish Cup, these boys have been good enough and strong enough to deal with that."
While Inverness have been preparing for a midweek Premiership game against Hibernian, McInnes has taken his team for a three-day break to sunny St Andrews.
"We're not overly blessed with facilities in Aberdeen at the minute, so we felt meeting up on Sunday night and getting away for a few days would be good for the players," he said.
"We've had a round of golf and been able to relax a little bit. There is work to be done as well. While we're here, we can work individually with some players and treat aches and knocks. The hotel caters for sports teams and they've been as good as gold, so it's been the right thing for the players."