The Stamford Bridge outfit have made a blistering start to their Premier League campaign, winning seven of eight matches to claim a five-point lead at the summit.
And while Saturday's 2-1 success at Crystal Palace was not as convincing as some of Chelsea's other wins this season, it was achieved in the absence of the injured Diego Costa.
Costa has made a stunning start to his Premier League career, netting nine goals in seven matches, but his on-going hamstring problem forced him to miss out.
Mourinho hit out at Spain's treatment of the forward on international duty and he will be without the striker again for the Group G fixture against Maribor.
That could mean Loic Remy may lead the line again or Chelsea legend Didier Drogba.
Chelsea top the group with four points from two matches and, ahead of a Premier League blockbuster at Manchester United on Sunday, Mourinho could be forgiven for rotating his squad.
Maribor's two gritty Group G draws have caught Mourinho's attention, though, and the Portuguese - aiming to be the first coach to win the Champions League with three different clubs - will keep things relatively similar.
"For Tuesday, I cannot make lots of changes because I cannot break the balance of the team," Mourinho said.
"I can change a couple. I don't think I am going to recover any player - I do not think Ramires will be available.
"[Andre] Schurrle won't be available, Diego [Costa] for sure is not available. So the players I have are the players I had [against Palace].
"So I don't have a lot to change but I'm going to make a couple of changes.
"It is a very important match to win, to finish the first three matches with seven points is a very important situation for us."
Chelsea, who have won their last five matches in all competitions, triumphed 1-0 at Sporting Lisbon last month thanks to a Nemanja Matic goal.
Serbia midfielder Matic said in the build-up that "nobody expected Maribor to take points off Sporting and Schalke", but that those results had sharpened Chelsea's focus.
Maribor have slipped to third in the Slovenian top flight after winning just one of their last four league matches.
And a 2-1 home loss to Celje on Saturday will have done little to boost their confidence.
Maribor did become the first Slovenian side to beat an English team in UEFA competition last season.
But defeating second-tier Wigan Athletic in the UEFA Europa League, as opposed to Premier League leaders Chelsea in the Champions League, is a very different prospect.
