N'Golo Kante and Christian Pulisic have been ruled out of Chelsea's Premier League clash with Aston Villa on Saturday.
Kante has not fully recovered from an ankle issue sustained in the 1-1 draw with Liverpool before the international break, while Pulisic suffered his own ankle injury during the United States' World Cup qualifier against Honduras on Wednesday.
Speaking at his pre-match press conference on Friday, Chelsea head coach Thomas Tuchel confirmed both players would miss the game against Villa and revealed that Pulisic had actually returned on crutches on Thursday.
"We have two players out: N'Golo Kante and Christian Pulisic," Tuchel said. "N'Golo still suffers a little bit from the injury against Liverpool."
Although Kante will miss the Premier League fixture, Tuchel added that he was confident the defensive midfielder will be available as the Blues begin the defence of their Champions League crown against Zenit next week. "We will try for N'Golo on Tuesday. That looks good," he said.
However, USMNT winger Pulisic is facing a longer spell on the sidelines. Tuchel continued: "Christian came yesterday on crutches. He has an ankle injury with about ten days."
With Kante out, new loan signing Saul Niguez could be in line for a full Premier League debut at Stamford Bridge on Saturday.
Saul spent the duration of the international break at Chelsea's Cobham training ground having been left out of Spain's squad for their World Cup qualifiers against Sweden, Georgia and Kosovo, while Chelsea's other central midfield options Mateo Kovacic and Jorginho were away with Croatia and Italy respectively.
Both players featured in all three of their countries' matches during the pause and only rejoined the rest of the squad on Thursday.
Speaking about the arrival of Saul and the reasons behind the move, Tuchel added: "We get to know each other in detail, find out if we're a good fit.
"Billy Gilmour was our fourth midfielder last season but with the Covid situation, the Euros and Copa America, I was concerned going into the season with only Jorginho, Mateo [Kovacic] and N'Golo [Kante]. Not because of a lack of quality of character, I'm the happiest coach there can be that we have these three guys, but things are unpredictable.
"The Club World Cup is in December and nobody knows how many games. If you have one injured, one suspended, you're in danger to overload players. So we were looking for an alternative and Saul was on the radar for Chelsea for many years. I was fighting for him at other clubs but it wasn't possible.
"So when it was possible to have a loan, we were excited. He was the type of profile we need to give Jorginho and N'Golo the break they need."