Kepa arrived at Stamford Bridge from La Liga side Athletic Bilbao before the beginning of the 2018/2019 season as the most expensive keeper in the world but has failed to live up to his price tag.
The Spain international was fairly good during his first season in England where he helped the West Londoners to Europa League glory and a top four finish in the Premier League.
Kepa’s ability was questioned last season when he came under intense criticism from fans and media due to a series of lackluster display.
The 25-year-old was subsequently dropped from the starting lineup after Lampard grew frustrated with Kepa’s lethargic performances.
Chelsea are said to be on the verge of signing Mendy to compete with Kepa for the number one spot at Stamford Bridge, and Schwarzer, who played for the Londoners at some point in his career, has tipped the Senegalese to displace the Spanish keeper.
“It’s obvious that there are questions marks over Kepa, I think his save ratio last season was the worst in the Premier League,” he told Goal.
“He clearly hasn’t had a good time there. I think it hasn’t been entirely his own doing – defensively Chelsea haven’t been at their best.
“I think the step up to Chelsea has been astronomical and add the fact that they’ve paid a world record fee for him, it’s been really tough.”
“I just don’t feel he’s progressed as far as they hoped he had hence why they believe they need to bring in another keeper to really push him.
“I’d be surprised if they brought in Mendy and didn’t wait too long before putting him in as number one. It could be very damaging [to Kepa] and he may feel he has little chance to retain it."