Gary Neville is "pretty certain" Jose Mourinho will leave Manchester United at the end of the season.
Mourinho watched his team fall to a 3-1 defeat to Liverpool at Anfield on Sunday to leave them 19 points off the top of the Premier League and 11 points adrift of the top four.
Mourinho -- who was omitted from the list of the world's top 10 managers in the 2018 ESPN FC 100 -- has a contract at Old Trafford until at least 2020 after signing an extension in January but Neville is convinced the club will be looking for a new manager ahead of next season.
"I'm sure Manchester United will change the manager at the end of the season at the latest," he told Sky Sports. "I'm pretty certain. We're all pretty certain of that.
"Jose Mourinho, before that Newcastle game [in October], looked beaten. He looked like he'd had enough."
Sources have told ESPN FC that United's stance on Mourinho's future is unchanged despite the defeat at Anfield with executive vice-chairman Ed Woodward continuing to back the 55-year-old ahead of the trip to Cardiff on Saturday.
Both David Moyes and Louis van Gaal were dismissed for failing to qualify for the Champions League and Mourinho faces an uphill battle to finish fourth after overseeing the club's worst start to a season for 28 years.
And while Neville accepts Mourinho's time in charge is coming to an end, he insists the problems at Old Trafford extend beyond the manager.
"Mourinho is not a mug," he said. "He's been one of the most successful managers of the last 20 years.
"United fans, they're not looking forward to going to the games. But that's not just now.
"That was under David Moyes and under Louis van Gaal. Now it's under Jose Mourinho. That's three managers who have all got good records -- good managers.
"That's why you have to say at this moment in time that something is broken."
Iker Casillas, who played under Mourinho at Real Madrid, was quick to join in the criticism of his former manager on Sunday by suggesting it was time for him to retire.
Mourinho aimed a dig at the Porto goalkeeper in a newspaper interview by saying he was "someone at the end of his career" before Casillas chose to bite back on social media following United's defeat to Liverpool.
He wrote: "According to a Portuguese newspaper, someone said that a player like me [37 years old] is at the end of his career. I totally agree! My question for that newspaper is: in the case of coaches, when and at which point do you see that they are no longer able to manage or train a team?"