A second-half substitute in a 3-1 friendly triumph over Mauritania in Accra, the winger could not finish the game as he immediately walked off the pitch and headed straight to the dressing room after being on the end of a challenge late in the game.
"The international break is always quite complicated, particularly at this stage of the season, because you can see a lot of injuries," Benitez told pressmen on Friday ahead of Monday's Premier League clash with Arsenal.
"The players are tired and a lot of the national teams are playing for something so they are pushing players.
"We have some knocks but Sean Longstaff is the only player who is injured for us at the moment. [Fabian] Schar has had another test this morning and he was fine, training with the team.
"Today, we have had Atsu, [Deandre] Yedlin and [Miguel] Almiron coming back from international duty. We will need to make sure that they are fine tomorrow.
"When a player returns on a Thursday evening, it is quite difficult to get them ready for a game on a Saturday. But this game we play on Monday, so we have time.”
Atsu is expected to play an instrumental role for Ghana in their quest to end a 37-year trophy drought at the Afcon.
He played a crucial role in 2015 as Ghana finished runners-up, his exploits winning him the prestigious Player of the Tournament award.