Muscat's men have one hand on the Premier's Plate after a 2-1 win over the Roar in Brisbane on Wednesday.
With two games of the regular A-League season remaining, Victory sit three points clear at the top.
Berisha, the club's marquee signing ahead of the 2014-15 season, finally got to return to Suncorp Stadium on Wednesday.
"I think he played the game two or three times in his mind to be honest," Muscat said after the game.
"I felt for him because he's had to wait so long before coming back. He was a little bit on edge the last couple of days but in a positive way.
"Now that he's got that one out of the way I expect him to be better on Saturday."
The Roar, who are seventh but guaranteed a top-six finish due to Perth Glory's salary cap breaches, will be hoping they can get the better of Berisha's Victory on Saturday.
Perth Glory - currently third and appealing the punishments handed down to them by Football Federation Australia - host sixth-placed Melbourne City on Sunday.
