LONDON — Chelsea striker Nicolas Jackson has been ruled out for up to two months because of a hamstring injury, manager Enzo Maresca said on Thursday.

One potential replacement, Marc Guiu, is also out “for a while” with a hamstring problem, Maresca said, leaving Christopher Nkunku as the player most likely to lead the line for Chelsea

Jackson was substituted early in the second half of the 2-1 win over West Ham on Feb. 3.

“We knew it was a muscular (injury), probably, but we didn’t know how important it was because his feeling and his reaction was quite good,” Maresca said. “We all thought that it was not a big injury but unfortunately he had a scan a few days ago, it is an important one, and it will be around six-eight weeks.”