Paul Pogba has revealed the debilitating effect that contracting Covid-19 had on his fitness.
The Manchester United midfielder tested positive for coronavirus in August, forcing him out of the France squad and into quarantine.
Pogba's form clearly suffered in the early part of the season, culminating in United's dismal 6-1 home defeat by Tottenham Hotspur in which he conceded a penalty.
The 27-year-old had started just one Premier League match since that Old Trafford debacle, but he was thrust back into the line-up at West Ham United on Saturday and responded with a stunning goal and a fine all-round display in their 3-1 win.
Asked how Covid-19 had affected him, Pogba said: "It's strange, it's hard to explain.
"Even in training, I would say to the fitness coach that I feel strange. It's not me. I get tired very fast and I'm out of breath really fast.
"The first game of the season, I couldn't run. I was trying. I spoke with the manager, 'I will start the game and let's see', but I was very out of breath and it took me a long time to get back to my fitness and to get back physically good.
"It's good to get back in the team and to score this goal to help the team get back in the game, it's very important for the team. I'm very happy for that.
"It's such a difference. I'm finding my rhythm as well. I feel so much better, I felt I could go again, control the game, getting the ball. That's what I like."
West Ham led at the London Stadium through Tomas Soucek, but Pogba hauled United level with a spectacular first-time shot from 25 yards.
The ball seemed to have curled out of play when United goalkeeper Dean Henderson punted it upfield to Bruno Fernandes in the build-up.
And Pogba added: "The kick from Dean was a bit... we didn't know if it was out or in, but we just went for it. I just went for it, I saw Bruno had the ball and I was free. I hit one in the first half, it didn't go well, but the second time it went in and I'm really happy with this."
Mason Greenwood and Marcus Rashford were also on target as United made it five wins out of five on the road this season.
Manager Ole Gunnar Solskjaer has, however, revealed that both Edinson Cavani and Anthony Martial are injury doubts ahead of tomorrow night's Champions League encounter wth RB Leipzig.
Uruguayan striker Cavani, who scored twice as a substitute against Southampton last weekend, was operating as the central striker against West Ham, but did not come out for the second-half at London Stadium.
French forward Martial was forced off the pitch after 62 minutes and was replaced by Juan Mata.
Solskjaer confirmed both strikers will undergo scans ahead of tomorrow's game, with United needing a draw to qualify for the last-16.
"It is unfortunate, sometimes you get muscle injuries. We lost Anthony and Edinson," Solskjaer said.
"Some games we have to do without players and I'm glad we've got the substitutions we have."