Lamichhane has left the Stars ahead of the finals series due to international duties with Nepal in their upcoming 50-over tri-series with Oman and USA.
Rauf flew back into Melbourne on Tuesday night after missing the last four BBL matches because of international duty. He made his T20 international debut for Pakistan in the three-game series against Bangladesh.
The Stars have lost their last three matches without Rauf and Maxwell said he was delighted to regain him despite losing Lamichhane.
"As much as it is a shame to lose Sandeep we do get another overseas [player] back in Haris Rauf who has taken the BBL by storm," Maxwell said. "I think he has 16 wickets in seven games."
"That's pretty incredible for your first tournament, bowling fast on wickets that haven't really had a lot of pace and bounce in most of the places we've played. So for him to get something out of them, he's aggressive, he takes the game on and suits the Stars game plan down to a tee. Hopefully, he can produce the goods for us tomorrow night as well."
The winner of the qualifier will host the BBL final next weekend while the loser gets a second chance in the challenger next Thursday.
The Stars' recent form slump, which includes a loss to the Sixers at the SCG, has not concerned Maxwell.
"I'm not too fazed," Maxwell said. "I think the way we've played this season has been pretty incredible and it's pretty rare to lock away top spot with three games to go in the season and we were afforded the luxury of being able to rest a few players that had certain niggles. We were able to get guys through to make sure they were 100% for the finals. It's worked out perfectly for us.
"To be able to play fresh guys at this stage of the tournament is very valuable."
The Stars rested quick Nathan Coulter-Nile for the losses against the Sixers and Adelaide Strikers, while Daniel Worrall was rested against the Brisbane Heat last Saturday. Worrall has been included in the 13-man squad for the qualifier alongside Rauf.
Maxwell was coy about who would open the batting with Marcus Stoinis in the absence of Hilton Cartwright who is out of the tournament with a broken finger.
"It's a good question, you'll have to find out tomorrow," Maxwell said when queried. "I'm 100% certain on what's going to happen tomorrow but you'll have to wait and see."
Nic Maddinson and Seb Gotch have both been tried in the last two games. Maddinson's form has been particularly troubling for the Stars. He's made just 116 runs for the tournament, averaging 10.54 at a strike rate of just 91.33, which includes a 40 against the Hobart Hurricanes in Moe before Christmas.
But Maxwell is backing Maddinson to fire against his old side after a net session with the Stars' list manager and batting mentor Trent Woodhill on Wednesday.
"He's good," Maxwell said. "He had a really good hit with Trent Woodhill yesterday and sorted some things out. Even speaking to Trent before, he's in a really good headspace, he's really excited for a match-up against his old side and he's as pumped as anyone. He's looking forward to tomorrow and I'm looking forward to seeing how he goes."