Chelsea striker Tammy Abraham was forced out of his side's Champions League encounter at Valencia on Wednesday in what could be a major blow for the Blues.
As the first half was winding down Abraham went up for a header with Valencia defender Ezequiel Garay and appeared to land awkwardly on the Argentine's legs as both players fell to the ground.
Abraham walked to the sideline in considerable pain as he appeared to be holding his side, with Chelsea physios examining him.
As the half-time whistle blew a stretcher was brought out for the England international, who had to be carried from the pitch.
The second half began with Michy Batshuayi – who spent part of last season on loan at Valencia – being brought on in Abraham's place with the score tied at 1-1.
The game would end in a thrilling 2-2 draw, as the hosts spurned a number of clear chances to gain a major win over their Premier League visitors.
Abraham has established himself as one of the top strikers in the Premier League in what has been a breakout campaign for the striker thus far.
The 22-year-old has scored 11 goals in all competitions for the Blues, including 10 in the Premier League in his first full season with the Blues senior squad.
Abraham had spent the previous three seasons on loan, gaining first-team experience with Bristol City, Swansea City and Aston Villa.
The striker has become part of a young nucleus of Chelsea homegrown stars who have made a major impact in Frank Lampard's first season at the helm.
With the club hamstrung by a transfer ban, the likes of Abraham, Mason Mount and Fikayo Tomori have become key figures on the senior side after coming up through the Chelsea academy.
If Abraham is forced to miss time then Chelsea's other two main forwards, Batshuayi and Olivier Giroud, will have to step into more prominent roles at Stamford Bridge as they look to fill the void.