The 23-year-old arrived at Old Trafford in 2017 after five years in Mourinho's native Portugal with Benfica, and initially struggled to adapt to the rough and tumble of the Premier League.
Despite a price tag reported to be 35 million euros (30.6 million pounds), he was initially used sparingly by Mourinho, who preferred to ease Lindelof into the side by playing him in cup competitions and the Champions League group stage.
Mourinho finally handed him his Premier League debut in October away to Liverpool and towards the end of the season the central defender, who can also play at right back, was a regular fixture in the team.
"I've learned a lot of things, it's been a good year for me," Lindelof told Reuters at a Swedish team media day ahead of their final pre-World Cup friendly against Peru in Gothenburg on Saturday.
"I've been playing with a lot of good players and I've been learning a lot from my coach, Jose Mourinho, so there's a lot I've learned this season."
Having made his debut for home town club Vasteras as a 16-year old, Lindelof left for Benfica a little over a year later and he went on to win three league titles with the Portuguese giants.
He broke into the Sweden squad that had already qualified for the Euro 2016 finals in France and played in all three group games. However, the Swedes failed to reach the knockout stage.
Plenty of big clubs came calling, but in the end Lindelof stayed another full season in Portugal before heading to United, where he has been studying the form of some of his World Cup opponents.
"I know the players that we are going to play against because they play in the Premier League. I've played against them and I know what type of players they are," Lindelof said, without revealing any names.
Sweden are set to face South Korea, Germany and Mexico in Group F in Russia, and Lindelof says the Premier League is perfect preparation for a demanding tournament.
"It's one of the toughest leagues in the world, every game is very tough. I think that's very good for players, it's important and you improve a lot day by day," he said.
(Reporting by Philip O'Connor; Editing by Christian Radnedge)
