Thomas Tuchel will take charge of his first Champions League game as Chelsea manager when his side travel to Bucharest to meet La Liga leaders Atletico Madrid in the first leg of their last 16 tie.
Facing Atletico was a daunting proposition when the draw was made, but with Diego Simeone's side on a run of one win in their last four games, Tuchel will smell blood and must take advantage of the situation.
Here's how he should set his side up.
West Ham United are among the sides keeping an eye on Chelsea striker Tammy Abraham, who has struggled for minutes under Thomas Tuchel.
Mason Mount has been Chelsea's best player in 2020/21, despite summer spending on Werner, Havertz & Ziyech, and even after Tuchel replaced Lampard as manager.
Tammy Abraham deserves better under Thomas Tuchel after he was dropped from Chelsea's matchday squad for the 0-0 draw with Manchester United.
Mason Mount discusses his role at Chelsea, relationship with Frank Lampard, development under Thomas Tuchel and his bond with West Ham's Declan Rice.
1. Goalkeeper & defenders
Edouard Mendy (GK) - Kepa Arrizabalaga played the last Champions League game, but he'll be dropped back to the bench for this one.
Cesar Azpilicueta (CB) - Surprisingly effective as an overlapping centre-back, Azpilicueta has been impressive in Tuchel's system and will likely retain his place.
Andreas Christensen(CB) - With Thiago Silva still out injured, the Dane will expect to continue at the centre of the back three after his impressive displays of late.
Antonio Rudiger (CB) - Kurt Zouma made his first Premier League start under Tuchel last time out, but he didn't do enough to convince the boss to bench Rudiger.
2. Wing-backs & midfielders
Reece James (RWB) - More of a natural defender than Callum Hudson-Odoi, James will be relied upon to keep Atletico's tricky forwards at bay.
Mateo Kovacic (CM) - We already know how much Tuchel loves Kovacic. Even though he wasn't great against Southampton, he's surely still going to keep his place here.
N'Golo Kante (CM) - One of Kante's best performances in a Chelsea shirt came away to Atletico in 2017, and Tuchel will hope for something similar here.
Ben Chilwell (LWB) - Marcos Alonso wasn't great against Southampton, so Tuchel should look to give Chilwell another chance to impress.
Mason Mount (AM) - Mr Chelsea. Mount's forward-thinking and high press will be crucial to destabilising Atletico's solid defence.
Timo Werner (AM) - Werner's recent resurgence stalled against Southampton, but he still deserves to keep his spot in the team, particularly with nobody else really staking a claim.
Olivier Giroud (ST) - Tammy Abraham looked both unfit and uncomfortable against Southampton, so Giroud seems like the safer option. His four-goal haul against Sevilla earlier in the competition is still fresh in the memory.