Schweinsteiger, 32, made just 18 Premier League appearances in total for United in his two-year spell, scoring once.
"I analyse the individual performances of the players, try to understand who can give me a little bit more for the final".
When asked what United need to do to compete next season, Mourinho added: "I don't want to think about it, I want to think about the final", before walking off camera.
"They've been the most consistent team in the league and thanks to that they were able to celebrate the title last Friday after defeating West Brom, so my honest congrats to them".
Manchester United are back in action on Wednesday night when they face Southampton in the Premier League.
"We know it's a big objective, we know that if we lose the final we don't play Champions League, we know that". We know that, but we fight for titles. "Because of my respect for [Tottenham], I didn't rest more people", said Mourinho, whose side visit Southampton on Wednesday.
But they have two more league games before that, with tomorrow's long trip to Southampton followed by a home game against Crystal Palace on Sunday.
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I think the point that I was making, Chuck, in that message to State Department employees is an important one to understand. However, "it's inconclusive as to what, if any, effect it had", he added.
"We had to do it because, if I have Ashley Young, Luke Shaw, Marcos Rojo, Ibrahimovic, Tim Fosu-Mensah, if I have these guys (who are injured), I can rotate, I can go for every match".
Explaining his decision, Mourinho insisted he will continue to make major changes for each of the club's last three league matches up until the final against Ajax in 10 days.
"I think after I trained and I played, and he could see how I behaved as a professional, he had a different opinion".
Mourinho shrugged off any disappointment surrounding a probable sixth-place finish for his EFL Cup winners - United have not finished lower since David Moyes' shambolic tenure in the 2013-14 season. We didn't choose Europa League - we had to do it!
"You know that in all of my career I was never out of European competitions in the group phases". Luck was in United's favour as they are also one step away from making it to the Champions League in the next season.
He said: "We don't worry about pressure and opponents. I wish them all the best", Bastian Schweinsteiger said as he was surrounded by local, national and global media.
The former Germany captain recently spoke of his frustration at playing at a lower level of football.