The Belgian, making his first domestic appearance after his three-game ban, came off with 15 minutes left at Saint Mary’s after picking up a knock to his ankle.
Anthony Martial, moments before Fellaini’s knock, rattled the post with a fierce drive but Mourinho’s men couldn’t break the deadlock.
And the Portuguese, speaking after the game, noted that the Belgian had nothing more than a “little bad feeling” when he came off, before adding that nobody else suffered a knock.
“Fellaini, on top of his experience, he says it’s not a tear,” he said. “On top of his experience, he says it was a minimal thing but minimal can be a big thing. Let’s wait for tomorrow but he needed to play.
“I couldn’t protect him as he needed to play. He didn’t play for three matches due to suspension. Players need not only to rest but also to play. He wasn’t playing a lot so he had to play today. I don’t blame myself or our decision but let’s wait.
“The one with little problems is the Bailly that can have little problems,” he added. “Eric, because he’s not playing the final [due to suspension].”
You sense that, in similar fashion to what was seen against Celta Vigo, Mourinho will use Fellaini in Stockholm as something of a deliberately unknown quantity. European opponents, I’ve noticed, struggle to understand Fellaini’s style, almost as if they’re encountering a new species for the first time, and his bombastic presence against Ajax could very easily lob a spanner in the works, as they say.