Kucherov had to cancel the victory match against Washington on Saturday after a collision with opposing forward Garnet Hathaway.
What kind of damage it is is not official.
Kucherov missed the entire regular season last season after a hip operation, but came back and won the playoffs scoring 32 points (8 goals + 24 assists) when Tampa Bay won its second straight Stanley Cup title.
Nikita Kucherov is also one of the Russian team's key players in the Beijing Olympics in February and is one of three players in the squad already selected.