According to Sky Sports News HQ's Kaveh Solhekol, the Ligue 1 champions demanded £40 million for Mendy, but City are looking good to snap up 27-year-old Bertrand:
Kaveh Solhekol @SkyKaveh
Manchester City making significant progress with deal for Southampton left back Ryan Bertrand after Monaco demanded £40m for Benjamin Mendy2017-6-6 07:58:40
Gael Clichy and Aleksandar Kolarov shared left-back duties for Pep Guardiola's Sky Blues in 2016-17, but the former has now been released by the club—along with Bacary Sagna, Jesus Navas and Willy Caballero.
City are in desperate need of new full-backs and Bertrand would be an ideal addition as he already has plenty of Premier League experience.
The 27-year-old is reaching the peak years of his career and won an FA Cup, a UEFA Champions League and UEFA Europa League during his time at Chelsea. Since his move to the south coast he has been a key part of a fine Saints squad.
The England international is defensively solid, he is both a ball-winner and intelligent reader of the game, while his attacking contribution is valuable—he netted two goals and provided four assists in the Premier League in 2016-17, per WhoScored.com.
Back in April, MailOnline's Kieran Gill reported Bertrand was a target for former club Chelsea, but the Blues would have to pay "at least double" the £10 million they sold him to Saints for in 2015.
City could easily afford to shell out around £20 million for the Englishman, and he would be a cheaper—and potentially better—option than Mendy given he already has proved himself in the English top flight.