Thiago Silva (left) helped Paris St-Germain reach their first ever Champions League final last term
Chelsea will be without defender Thiago Silva for the first leg of their Champions League last-16 tie against Atletico Madrid on Tuesday.
However, midfielders Kai Havertz and Christian Pulisic are fit again and could feature in Romania.
Atletico's injured absentees include Jose Gimenez, Sime Vrsaljko and Yannick Carrasco, while Hector Herrera recently tested positive for Covid-19.
But Luis Suarez and Joao Felix should both start for the La Liga leaders.
Kieran Trippier also misses out for the Spanish club, with the England full-back still serving a suspension for breaking betting rules.
Chelsea go into the tie unbeaten in seven matches in all competitions since Thomas Tuchel replaced Frank Lampard as manager in January.
But while a switch of venue from Madrid to Bucharest due to coronavirus travel restrictions will be a "disadvantage" to Atletico, Tuchel says the game will still provide his side with a huge challenge.
"It's a big test. They're an experienced club at this level, (have) an experienced coach. Hopefully it brings out the best in us," said Tuchel.
"We'll do things our way, they'll do things their way. It's clear what you get when you play Atletico – fighting, experience, a team with a good mentality."
One player that Chelsea will need to pay particular attention to is former Liverpool and Barcelona forward Suarez.
The 34-year-old is La Liga's joint top goalscorer with former teammate Lionel Messi and Tuchel says he tried to sign the Uruguayan while he was still the Paris St-Germain boss last summer.
"He is a natural-born striker. He has the certain mentality that only strikers have," said Tuchel. "This mentality to show his will, intensity and anger to score and score and score and is never satisfied."
Rank outsiders Chelsea
Entertainment data company Gracenote say Chelsea have a 39% chance of advancing past Atletico to the quarter-finals of the competition.
Simon Gleave, head of sports analysis at Nielsen's Gracenote, said: "Chelsea are one of the outsiders to win this season's Champions League. Their chance of doing so is currently 2%."
The overall head-to-head between Atletico and Chelsea in European competition is perfectly balanced, with two wins each, three draws and 11 goals each.Atletico prevailed in their only previous Champions League knockout tie with Chelsea in the 2013-14 semi-finals (3-1 on aggregate).Atletico have reached the knockout stages of the Champions League for the seventh time in the last eight seasons. Meanwhile, Chelsea will attempt to progress past the round of 16 for the first time since the 2013/14 campaign (semi-finalists).
Simeone has never lost a home match as Atletico manager in the knockout stages of the Champions League (Won nine, drawn four). Atletico have only conceded one goal in their last 12 Champions League knockout ties at their Vicente Calderon/Wanda Metroplitano stadiums, that was against city rivals Real Madrid in May 2017 (2-1).Atletico scored only seven goals in six games in this season's group stages, the lowest tally amongst the 16 remaining sides in the competition.Suarez has never failed to score or deliver an assist in a Champions League campaign – this is his eighth season in the tournament. He is so far goalless and assist-less in his four games with the Madrid side in 2020/21.
Chelsea are the last team to beat Atletico on their own turf in European competition – it was in September 2017, Atletico's first European match at their new Wanda Metroplitano stadium (1-2).Chelsea were trailing for a grand total of four minutes during this season's Champions League group stages, less than any other side. Also, only Manchester City (one) conceded fewer goals than the London side (two) in the group phase.Chelsea were one of only four teams to win all three of their away games in this season's group stages, alongside Atalanta, Barcelona and Juventus; they also scored more goals on the road than any other side (10). However, their last away win in the knockout stages of the competition dates back to March 2012 against Benfica (1-0).Chelsea striker Olivier Giroud found the net every 28 minutes in the Champions League group stages this season (five goals in 142 minutes), the best ratio of any player to score more than one goal.Of keepers to play at least three Champions League games this season, Chelsea's Edouard Mendy has the best save percentage in the competition (94%), only conceding from one of the 16 shots on target he has faced so far.