Having been deemed worthy of the sixth overall selection at the 2008 NAB AFL Draft on the back of his stellar junior years as a forward, Yarran had understandable reservations about being recast as a defender.
But there was one feeling that overrode the myriad of conflicting thoughts tumbling through his mind: I want to play with my mates.
Yarran formed a strong bond with Eddie Betts and Jeff Garlett early in the piece, but when he played AFL footy in 2009, Garlett did not.
After a season where the three of them fought over two spots, the small forward trio finally made it into the same team in round four last year. They played an important part in snapping a seven-game losing streak against the Crows in Adelaide and the 'Three Amigos' were born.
The threesome proved highly effective inside forward 50 over a six-match run until a quad injury suffered by Yarran broke the sequence.
Garlett didn't lose his spot when Yarran returned, but when the coach opted to go with Betts and Garlett in a dual small forward set-up against the Sydney Swans in the elimination final, Yarran saw the writing on the wall.
"I'm really good mates with those guys and to have three small forwards in the team … in the long term I'm just not sure how that was going to work," he says.
"It was going to be hard for them to find spots for us all up forward every week.
"I'm pretty close with Andrew Walker up there as well, so we just wanted to try and find a way for us all to play together week in, week out. I couldn't see that happening with me in the forward line as well.
"I was pretty surprised when Ratts first came to me with the idea because I was drafted as a forward, but you've just got to try and adapt to whatever role you're given.
"If that suits the team more then I'm happy to do it."
Switching from one end of the ground to the other was no small feat for Yarran.
His instinctive goal sense and knack for reading the ball off a pack were weapons for him in attack as a youngster, but he had to develop a whole new set of skills if he was to make a go of it down back in elite company.
"As a forward you pretty much just chase the ball around and try and hunt the footy up, but it's quite different down back," he says.
"You've just got to try and lock onto your man and shut him down first and then attack second.
"Ratts has given me the confidence to run and carry, but he says that if you defend first then the other stuff will come naturally. I've been lucky enough not to have had a bag kicked on me yet and hopefully that trend continues."
The West Australian won rave reviews in his new role during the pre-season campaign and soon found his feet after a quiet start to the season proper.
He freely admits he's still got a lot to learn, but credits backs coach Gavin Brown and teammates Michael Jamison and Jordan Russell as key figures in his ongoing education along with a childhood idol who has been an unwitting mentor.
"I've had a look at Andrew McLeod's tapes and the way that he used to go about it," he says of the 340-game Crows superstar.
"I've tried to pick up on some of the things that he did over his long career. He was a champion of the game and if I can match half of what he did then I'll be fine."
