The Portuguese returns to United as a manager for the first time since being sacked by the Red Devils in December 2018.
He was appointed Tottenham boss on November 20 – just a day after Mauricio Pochettino's dismissal – and has steered his new side to three consecutive wins across all competitions.
Mourinho guided United to EFL Cup and Europa League triumphs during his two-and-a-half years in charge and Solskjaer has no doubts he will be well received on his return.
The Norwegian told a media conference: "[He will receive a] very good reception; that's just a testament to this club and these supporters.
"Of course, they remember the two-and-a-half years when he won trophies. So, for me, I'm 100 per cent sure our fans, staff and club will welcome him."
United have endured a difficult start to the campaign and are languishing in ninth after just four wins from their opening 14 games.
Solskjaer acknowledges his side must improve but does not think his players need the motivation of playing against their former boss to get back to winning ways.
"I don't think whoever the manager of the opposition team is will change [the players'] motivation," he added.
"They're motivated to do well for Manchester United, for themselves, for us as a group going forward. They also know it's about improving every day in training, but every time you step onto that pitch, it's a chance to be a part of this long-term.
"And that's always been the case at Manchester United when you put the shirt on; it doesn't matter who you play against, you've got to give it your all. The boys are a bit disappointed after Sunday [when they drew 2-2 with Aston Villa] but now it's all eyes on Wednesday."