Predecessor Pep Guardiola rotated his players a lot during his three seasons in charge but never won the Champions League with the Bavarians.
Ancelotti, who took over in the close season, said there would be some minor adjustments from Friday's Bundesliga win over Schalke 04.
"The competition starts tomorrow and it is important for us to give it our very best from the start," the Italian told reporters on Monday.
"I will not be undertaking any major rotation. There will be some changes but I do not know yet which players.
"For me there are two tasks for a lineup," said Ancelotti. "The team must be kept fresh and the team must be motivated."
Bayern have won the Bundesliga for the last four seasons and are top with two wins in two matches.
Another triumph over Rostov would make it 13 Champions League home victories in a row for Bayern, surpassing Manchester United's record set in 2006 and 2008.
Ancelotti will be without winger Arjen Robben and central defender Jerome Boateng who both trained on Sunday following injuries but are not expected to join the rest of the squad until next week.
Winger Kingsley Coman, back from his injury, will also not be available as he prepares for his league comeback on Saturday.
Bayern have been drawn in Champions League Group D along with last season's runners-up Atletico Madrid and PSV Eindhoven.
(Reporting by Karolos Grohmann; Editing by Tony Jimenez)
