The Swedish attacking star scored a goal, but was substituted early in the second half when Newcastle defeated Brentford on Wednesday with 2–1.
At a press conference on Friday, Newcastle's manager Eddie Howe confirmed that it was a precautionary measure as Isak sustained an injury already during the warm-up before the match.
It did not prevent the attacking star from scoring his 20th league goal for the season.
Newcastle, who are chasing a Champions League spot, also have question marks for Kieran Trippier and Anthony Gordon, the latter having been out for a while.
We'll have to wait and see. Hopefully, they'll feel okay. We don't think we have any serious injuries from Wednesday's match, it's more about niggles, says Howe according to The Standard.
