Dwight Yorke says Joe Hart can feel hard done by after being dropped from the Manchester City team.
Costel Pantilimon has started in goal for City's last two fixtures - a 2-0 Capital One Cup win over Newcastle and the 7-0 Premier League thrashing of Norwich - and is set to play in the Champions League clash with CSKA Moscow on Tuesday night.
Sky Sports pundit Yorke says Hart may have rebuilt his confidence had he played in Saturday's big win and will be frustrated at losing his place ahead of a big European night, but says the England goalkeeper must now rise to the challenge and force his way back into the side.
"The manager is there to make difficult decisions," Yorke told Sky Sports.
"This is the England number one we are talking about. Since he has taken over the reins from Shay Given, he has played 123 consecutive Premier League games for City and has been their number one player for a number of years.
"This is going to be a testing time for him. As a player, you want to play in every game and he's going through a phase where he has not played his best and you feel that his position is under threat. At this level when you're playing for such a top club, you've got to be performing week in, week out.
"He will probably think he's been hard-done-by because of all the good saves and good play in the past, but at this level when you do slip up there are people waiting.
"Obviously the manager thought it was time for a change. Pantilimon has played in the League Cup and pulled off some good saves against Newcastle and has got his chance.
"Whatever little he needed to do against Norwich, he did extremely well, although he didn't have any major saves to make. That will give him confidence.
"Hart will probably think he's hard-done-by because Norwich is probably a game he would have liked to have played in to get his confidence back.
"Pantilimon was given the opportunity and City cruised to a 7-0 victory. That will play on his mind for a little while and the manager has got a dilemma over whether to carry on with Pantilimon or bring back Hart.
"It's going to be a challenging time, but that's what football is all about when you're a top player. You are tested and I'm sure from an England perspective they will want to see him back in goal as quickly as possible."
City won in Moscow two weeks ago and will go into the return clash on the back of the biggest margin of victory in their Premier League history.
Yorke isn't reading too much into the 7-0 whitewash of Norwich because of the frailties of the away side, but says Manuel Pellegrini will be delighted by the way his team are sharing out the goals.
He added: "Normally when you see a result like this, you tend to think that your top scorer - Sergio Aguero - will probably get two or three and people like Edin Dzeko will probably end up with a couple.
"But to have seven different scorers shows strength within your squad and that's very pleasing for the manager.
"People like Aguero will probably think 'I should have got three or four goals', but it didn't quite happen. Yet it's very encouraging from City and will give them extra confidence going into the rest of the campaign.