Liverpool goalkeeper Simon Mignolet said his mental strength enabled him to step up and replace Loris Karius against Middlesbrough on Wednesday.
The Reds midweek clash saw the Belgian international replace Karius in goal after the German committed a string of high profile errors.
Mignolet kept a clean sheet in the 3-0 victory over Boro and will start between the posts again in Mondays' Merseyside derby with Everton.
"In football, things can change very quickly with an injury or an illness. Therefore you have to look after yourself, stay professional, keep your head down, work hard on and off the pitch and stay focused, which is not always easy, especially as a 'keeper," Mignolet said.
"As a striker you can come on to help the team at certain moments but here you have to wait for your chance to come and try to be ready.
"I only knew I was playing on Tuesday and then I had to focus on my own job to make sure I was ready to play. You have to be mentally strong as a 'keeper.
"I always try to be ready in this kind of period."
Mignolet has been no stranger to goalkeeping mistakes during his time at Anfield, and the 28-year-old says Karius must be given time to prove himself.
"The goalkeeper position is not an easy one. You can only speak about it if you are a goalkeeper yourself," he said.
"We are team-mates, so of course I have sympathy. I am 28 now and I have been through it as well. At a club like Liverpool, one mistake gets really big out of nothing. I know what it is like and it's not nice.
"The most important thing is Liverpool football club. No individual is more important than the club.
"Obviously for Loris it won't be nice but he is more than capable and professional enough to deal with that and learn from it. He will get stronger."