He made just one senior appearance in an EFL Cup first-round defeat at Reading in August 2018.

"I'm a Blues fan but on Saturday I want to batter them. I want to win," Scarr told BBC Radio Devon.

"I enjoyed it there, even though I never got out of it what I wanted to - it never really worked out, but I have always had a soft spot for them, I watch their highlights and as soon as I pick up my phone I know how they got on through my mates who are Blues fans.

"It's just a normal game that I want to go and win. It makes it better that a lot of my mates will be there - some in the Argyle end and some in the Blues end. I'll have plenty of support... and probably some boos!"

Argyle are back in the second tier following last season's promotion and have taken four points from their first three games, as well as progressing to the second round of the EFL Cup.

Scarr made 36 appearances in 2022-23 and has started all three league matches this term.

Boss Steven Schumacher believes Birmingham are "dark horses" in this season's Championship following the takeover by Tom Wagner and NFL legend Tom Brady and have made nine signings in the transfer window.

He told BBC Radio Devon: "There's a lot of excitement about the team. They're recruited incredibly well. It's a club in good spirits at the moment. It'll be a tough game."