Thomas Tuchel knows Paris Saint-Germain will face a Manchester United side revitalised under Ole Gunnar Solskjaer in the last 16 of the Champions League.
After qualifying top of a group that also included Liverpool and Napoli, the Ligue 1 champions were dealt a tough hand in the first knockout stage when drawn against United, albeit much has changed since the teams were paired together at the end of last year.
Jose Mourinho was in charge of the Red Devils at that time, but the Portuguese was sacked soon after and replaced by Solskjaer on an interim basis.
The change in management has led to a stunning turnaround in the team's fortunes - United have triumphed in 10 of their 11 games under the Norwegian, with Burnley the only side to stop them winning in his reign so far.
In contrast, PSG will be without the injured Neymar for both legs of the tie, while Edinson Cavani is set to miss Tuesday's game at Old Trafford after picking up a hip problem at the weekend.
"Manchester United play with a lot of confidence, score a lot of goals, get a lot of early leads. It's an impressive run," Tuchel told the media.
"To play at Old Trafford against this Manchester United is like the group stage again. It's one of the toughest challenges.
"We were in extremely good shape at the end of the group stage. Since the draw, things have changed completely. I always said to talk about it in February.
"They are full of energy and full of confidence and it will be a tough challenge."
Tuchel refused to be drawn on what Solskjaer had done to achieve such impressive results but does expects United to be bold in their approach - just like their caretaker manager was during his playing days at the club.
"I'd love to have a good answer but I'm not sure it's on me to talk about the situation. Obviously, there is an effect," the former Borussia Dortmund boss said.
"We have a word in Germany: if you go to the doctor and he heals you, he's right - it doesn't matter how!
"He [Solskjaer] was a super dangerous player, any time he came on he was there to win games and he does the same as a manager here. It's a big challenge to play against him."