Chelsea have massive fears that Mason Mount could be out for the tie versus Atletico Madrid.
The in-form Chelsea star was seen icing his knee after the 1-1 draw raising concerns about his fitness.
However, he has now ensured the Blues that he is ready to play.
Mount told the club’s website after the game: “It’s just a little knock. A bit of bruising but I’ll be fine. Nothing can stop me.”
Mount scored the only goal against Southampton, from the spot.
“Tammy Abraham was actually taking the first one but obviously he went off at half-time so it was either me or Timo,” Mount added.
“The manager said it should be whoever feels confident on the pitch so I just stepped up.
“I missed my last one at Tottenham in the Carabao Cup so I wanted to make it right and I was confident in scoring as well.
“I’ve said before that it does mean a little bit more to me [to score against Southampton] and I scored here last season as well so it’s a nice ground for me to play at.
“But the most important thing is to get the three points and we didn’t manage to do that so it’s obviously a disappointment.”
See More: Chelsea vs Atletico Madrid Live Stream