While it remains to be seen who will be between the posts for today’s big cup meeting with Arsenal, with Berger having returned between the posts for the 7-0 win over West Ham, Musovic has been the goalie in many of the recent games and has eight appearances to Berger’s 13 this season.

‘Competition is healthy for players and as I always say to the players, it's important how you respond to that,’ Hayes says.

‘I want to challenge the team to serial winning and you can't do that with just the same set of players all playing in everything all the time. We've developed more depth in this period and the battle and the challenges that have gone on between our goalkeepers is certainly healthy for the present and the future of Chelsea.’

• Chelsea Women are playing Lyon in a big Champions League game - make sure you are there!

Berger’s quality is emphasised by her being one of the final three in the running for the Best FIFA Women's Goalkeeper award, with the winner to be announced on Monday. Meanwhile, Musovic signed a new Chelsea contract earlier this month.

‘Zecira has progressively over a period of time not only trained to a brilliant level, she’s earned my trust in big moments,’ Hayes explained.

‘One of the things I always ask for in players is if you want to play at the top level, you have to recognise that it's a daily challenge to find all those little things you need to do to do that.

‘Zecira certainly applies herself. Understandably, she is still lacking the experience that Ann has but she's certainly going in the right direction. She's still learning. She is most definitely one of the most improved players in this group and one who I really value.

'I think she will go on to really big things because her attention to detail, her attention to self, her application is second to none. She has an unbelievable winning mentality and she has an appetite to train which I really admire.’

Hayes also describes the 26-year-old Swedish international as a big personality who is extremely competitive and extremely ambitious, with an attention to detail.

‘She's bright, educated, thoughtful, funny and an outstanding team-mate,’ the manager adds.

‘She’s been in many, many situations when she hasn't played games and she's been exemplary in that and popular. Everything she's asked to work on she does. She's an A student. That's what I'd call her.’