The reinstatement of the left-back could have an impact on owners of team-mate Leroy Sane (£9.7m).
Sane has enjoyed a standout season, his eight goals and 11 assists contributing to his status as the seventh-highest scoring player in FPL.
But in the latest edition of the FPL Show, expert David Munday fears for what Mendy's return could mean for his German team-mate.
"The reason Sane has been getting a place in the team is because there's been no competition for him on that flank," says Munday.
"But now there is competition and with Pep [Guardiola] you just never know what he is thinking."
When Mendy has played this season, Sane has started only two of nine matches, as opposed to the 13 out of 14 when the Frenchman has been out.
Yet Sane has scored a goal or created an assist every 50 minutes with Mendy in the side, compared with every 75 without.
To further confuse matters, City's progress to the EFL Cup final is another reason for managers to consider their players with caution.
"Man City won't have a fixture in Gameweek 27 so we do have to temper our interest," Munday says.