Chelsea lost to Basle in the opening round of matches and are bidding to make amends at the National Arena in the Romanian capital.
Chelsea have been here before, with Raul Rusescu's first-half penalty earning Steaua a memorable win in the Europa League last 16.
"It's good for me," he said. "They lost, they know why they lost, they know it's not easy.
"Last season maybe was a bit of a surprise and this season they know they are going to play against a good team."
Mourinho is without playmaker Eden Hazard (ankle) and his fellow Belgian Kevin de Bruyne, who was left at home after failing to impress his manager.
The Portuguese was frustrated to once again be asked about a player not involved due to his non-selection, just as he was with Juan Mata in the early weeks of the season.
Mata will play on Tuesday night, Mourinho has said.
Another probable starter is midfielder Frank Lampard, who insists there will be no complacency on this occasion, with Chelsea knowing what to expect after experiencing a team roared on by a raucous crowd in March.
"You can never underestimate any team in the Champions League," Lampard said. "In the first game we didn't perform well, we lost. That's what happens.
Source: PA
Source: PA