A €45 million ($72.7 million) signing from Barcelona, Malcom has only featured twice since swapping the LaLiga champion for Zenit.

The Brazilian forward has not played since Zenit's 2-0 win over Dinamo Moscow in the Russian Premier League on 11 August (AEST).

"I have a very delicate and sensitive injury," the 22-year-old said.

"It seems that it hurts one day or two and then I don't feel pain, but when I shoot with a little more strength it hurts me again.

"The fans of the club shouldn't worry, [as] my recovery will be very fast and I will play again as soon as possible to give them joy.

"When I return, I will do my best as always. I want to play in the Champions League with Zenit."

While Malcom is dealing with an injury, Zenit is fighting for championship honours in Russia and competing in the UEFA Champions League.

Defending champion Zenit has only lost two of its opening 11 games to be fifth and two points adrift of leader CSKA Moscow.

Zenit also beat Benfica 3-1 in midweek to be top of Group G in the UEFA Champions League after two match days.