Former Manchester City striker Paul Dickov warned the club's players they are on trial for the rest of the season ahead of the arrival of Pep Guardiola.
Guardiola will replace Manuel Pellegrini at the end of the Premier League season after his appointment was finally confirmed on Monday.
Dickov, who had two stints at City, said the remainder of the campaign was an opportunity for players to prove themselves to the Bayern Munich coach.
"You don't play for Manchester City and compete for trophies at the top level if you're not mentally tough," the former Scotland international told Omnisport.
"The players will probably be quite glad that the speculation has been quelled and, if anything, Pep will be watching.
"You talk about competing on all four fronts – if they end up not winning a trophy, is Pep going to keep those players next year?
"They've got to prove that they're successful, that they're hungry and they want to win things, otherwise they'll be out of the door.
"Pep will come in with a clean slate, carte blanche to sign the players that he wants and bring the young players through if he likes.
"If anything, from now until the end of the season, the players are on a bit of a trial."
City sit second in the Premier League and are still alive in the Champions League and FA Cup, as well as reaching the League Cup final.
Despite that, Pellegrini will depart at season's end – and Dickov said it was an indication of just how hungry City's owners were for success.
"It's a massive statement of intent from the owners. I remember going back a few years ago when they got rid of Roberto Mancini, a few fans were questioning whether it was the right move," he said.
"They've brought Manuel in and he's gone on to win the League Cup in his first season and win the league.
"It makes a mockery of being successful as a manager, if you think about it. But the owners have shown since they've come in that they want to progress.
"The ultimate goal for them is the Champions League and there's no doubt about it that the best and most successful manager in the world over recent years is coming in now."