The 54-year-old Englishman joined the Ayrshire club in 2017 as Steve Clarke's right-hand man, and is also part of his backroom team with the national side.

But who is Dyer and could he be Kilmarnock's next manager?

BBC Scotland looks at his career.

Playing under 'Big Sam' and sports science

Dyer had a 19-year professional career as a player in England, and briefly Portugal, spanning eight different clubs with over 450 appearances. But despite extensive experience as a player, Dyer did not get into management immediately.

He trained to become a fitness coach and personal trainer and worked as a sports coach at a London school before joining the sports science department at West Ham in 2004.

It was not long before he made the transition to coaching, though, as he took charge of the London club's reserve team until 2011, when he joined Charlton as assistant to his friend Chris Powell.

The pair managed to steer Charlton back to the Championship with a record points haul, and took them to ninth place in England's second tier the following season.

After following Powell to Huddersfield for a year, Dyer then had a spell in caretaker charge of non-league side Welling United.

He has worked with Avram Grant, Sam Allardyce, Eddie Gray and Steve Coppell in a varied coaching career but as yet has little experience as a manager.

Dyer worked alongside Chris Powell at Charlton and Huddersfield

Part of Rugby Park revolution

Dyer and Clarke's relationship goes back to West Ham, when the Scotland head coach was assistant manager to Gianfranco Zola and Dyer was reserve team boss.

Clarke and his staff took Kilmarnock from bottom of the league in October 2017 to fifth place by the end of the season, and then third a year later.

In consecutive seasons the team broke the club's record points tally, took the scalps of Celtic and Rangers, and secured European football for the first time in 18 years.

The success led to Clarke's appointment as Scotland boss, and Dyer turned down the chance to replace him, opting to remain as assistant while taking up the same role with the national team.

Could the Englishman be about to get a second chance?

'Well respected by players and fans'

Sandy Armour, editor of 'Killie Hippo' fanzine, on BBC Scotland's Sportsound

There was a fair shout for Alex Dyer to be appointed manager when Clarke left because he was a big part of the success we had. He was very well respected and liked by the players and fans.

I don't know if his position has changed on that [turning down the role of manager]. If he can improve us in the next few games and pick up one or two wins along the way, he's in pole position for the job. But I don't know if he wants to do that or if he would just like to continue as an assistant.

What I witness with Alex at the games with the fans is the way they respect him. Even with the players. You see things like the body language of players when you're at games and think 'they like him'.