Premier League leaders Chelsea lost for the first time since April on Saturday, as Newcastle United claimed a surprise 2-1 home win.
Mourinho's men - who had already qualified from the UEFA Champions League's Group G, and won it - responded well at Stamford Bridge on Wednesday.
Cesc Fabregas and Andre Schurrle scored in the first 16 minutes and a rare John Obi Mikel strike wrapped up the three points for Chelsea in Europe's premier club competition.
The result saw Sporting exit the competition but Mourinho was pleased with his side's response and attitude in a match that meant little for his side.
"We were very focused and serious," Mourinho told Sky Sports.
"I'm happy with that. I feel sorry for Sporting. I would have liked them to qualify.
"[The win] was important.
"It was a good reaction to losing at Newcastle and a good chance for players to have more minutes. I'm happy with many things we did.
"We have a good squad. It was a game without pressures - it was quite an easy game to play."
Schurrle's goal was the highlight of Chelsea's performance as the forward turned and fired into the bottom-left corner from 20 yards.
He put in an impressive performance but Mourinho - who revealed that the 24-year-old had been struggling from illness - said that he still has work to do to become a Premier League regular.
"Andre Schurrle is in my plans when he's in top form," he added.
"He came back from Germany duty very ill. It's taken him time to recover.
"He needs to adapt better to the Premier League."
‘After Manchester City’s recent form, maybe they’re the underdogs against Manchester United!’ Former Red Devils defender on this weekend’s derby
‘Arteta, Alonso, Emery, me… none of us were physical players – we needed the understanding of the game. That probably helped us move into management’: Premier League boss reveals reasons for natural career progression
