Right-back: Reece James (Chelsea)
There's no full-back in the world in better form than Chelsea's Reece James. He has scored and assisted four goals apiece in the league so far this season, numbers that can put an attacker to shame.
He also leads all Premier League defenders with the most chances created (2.8) in open play this season.
James has evolved massively under Tuchel. His speed and explosive energy down the flanks add a new dimension to Chelsea's attack. Meanwhile, his exquisite crossing ability is key to creating chances.
Centre-back: Antonio Rudiger (Chelsea)
Another player who's having a fine season is Antonio Rudiger. The Chelsea centre-back delivered a defensive masterclass in the 4-0 drubbing of Juventus in the Champions League.
He has become adept in ball-recoveries, and refined his game-reading acumen. As was seem on Wednesday, the German is highly effective in counterpressing and laying progressive passes too.
Centre-back: Thiago Silva (Chelsea)
Thiago Silva must have surely found the elixir of youth. It's difficult to believe he's 37, considering his top-notch performances and consistency in Chelsea's defence.
His longevity is rarely discussed. Nevertheless, his commitment was on show on Wednesday when the Brazilian produced a superb goal-line clearance against Juventus.
Left-back: Marcos Alonso (Chelsea)
Ben Chilwell's injury opens up a chance for Marcos Alonso to come into the Chelsea XI. He can now make a case to start as he also completes our all-Chelsea back-four in our hypothetical lineup.
The Spaniard has once again fallen behind in the pecking order. His attacking output isn't as glorious as Chilwell's, but defensively, he has been superb.