Manchester United's Romelu Lukaku, top, duels for the ball with CSKA Moscow players during the Champions League soccer match between CSKA Moscow and Manchester United in Moscow, Russia, Wednesday, Sept. 27, 2017.
And Mourinho concedes the 24-year-old's workload will not get lighter until Ibrahimovic returns, which the United boss has suggested may not be until the new year.
Marcus Rashford and Jesse Lingard were useful second half substitutes for Mourinho and he still had the experienced Juan Mata in reserve as their cruised to their biggest Champions League away win since their 5-0 win against Bayer Leverkusen in 2013.
Lukaku has made an impressive start to life at United, scoring 10 goals in nine games in all competitions since arriving from Everton. Since arriving at Old Trafford, Lukaku has averaged one goal per 90 with a shot accuracy of 70%, and is the league's top goalscorer alongside Alvaro Morata and Sergio Aguero.
"But they are back competing and you expect them to be in the latter stages of the Champions League and winning the Premier League".
"Of course it is nice for a striker to score, it is nice for him to equal the record of such a legend in the Premier League like Andy", Mourinho said to Sky Sports after the match.
"He was a bargain at £75m". He's got off to a good start, and seems like a decent character.
The Portuguese manager said Lukaku had taken his opportunities well.
United struggled for goals last season and were overly reliant on Zlatan Ibrahimovic to deliver the goods, though he often missed some big chances despite a highly respectable final tally of 28 for the campaign.
Last season, United were guilty of being profligate in front of goal leading to them drawing several games.
"The big test will be in the big games".
Former Manchester United striker Owen is backing Manchester United to win to nil against Hodgson's men when Palace make the daunting trip to Old Trafford on Saturday afternoon.