The French full-back could be in contention to figure in our opening group C fixture away to Shakhtar Donetsk on Wednesday night after his return from a long-term knee injury.
A metatarsal problem, followed by successive knee injuries, restricted Mendy to just 15 appearances in our Fourmidables campaign and he missed our summer tour of Asia in order to focus on regaining his fitness.
But having returned to training and looking sharp the Frenchman is part of the City squad which has travelled over to the Ukraine.
And Zinchenko, who has deputised at left-back for much of the Frenchman’s absence, says his return is a huge boost for the squad.
“I’m so happy he is back, he lost so much time and everyone saw how much he worked on his recovery,” said Zinchenko.
“He’s so important playing for us. It’s a long season and (there are) lots of competitions so we need lots of players. I’m happy for him.”
City have been installed as one of the pre-tournament favourites for the Champions League but Zinchenko insisted that the Club would not be prioritising the tournament above any other trophy.
Instead, he said City had a desire to succeed in every competition.
“We must concentrate on our own game and of course a priority is the Champions League where we need to win,” the Ukrainian international added.
“But it’s our goal and desire to play well in all competitions we take part in.
“We respect Shakhtar and we want to just go out there and show our best game.”
It’s the third successive season that City have been drawn against Shakhtar in Europe and Zinchenko joked that Kharkiv, where Shakhtar play their home games, was almost becoming a second home for Pep Guardiola’s squad.
“Ukraine is the best country in the world!” Zinchenko added. “It’s (the team's) third time here so they know the city of Kharkiv very well and some are already looking to buy apartments!”