The 28-year-old will play his 200th game this weekend and he said the challenge of playing in defence had refreshed him mentally.
The former Magpie was one of Fremantle’s best on Sunday night, keeping the dangerous Brad Johnson goalless.
He said he had embraced coach Mark Harvey’s pre-season challenge to change positions after 11 years as a key forward.
“He (Harvey) made it clear to me early in the pre-season that he was looking to try me in a variety of roles this year and use my strengths for the team,” Tarrant said from Fremantle Oval on Monday.
“I accepted it and I thought this could be the spark I needed coming into my 12th season.
"Just that extra spark that I might need to really have a good year.”
Tarrant said he was nervous approaching his first game in defence but appreciated having the confidence of the Fremantle coaching staff in the new role.
He said it was a work in progress and by no means his permanent position for the rest of the season.
"I don't think I will play always as a backman, I think Harves has made it clear that I will be moved forward at times," Tarrant said.
"If I am down back I think I'll just take each game as it comes and being able to play on a tall and a small does give the coaches a variety of people [for me] to play on.
"The coaches have given me the confidence to play down back, which is fantastic."
Fremantle enforcer Dean Solomon is available to return for the milestone match on Sunday after serving an eight-match suspension for his hit on Geelong's Cameron Ling in round 15 last season.
Tarrant was hopeful former Bomber Solomon would come straight back in to the side to face Essendon at Docklands, saying it would be a dream come true to play his 200th game alongside his best mate.
"I'm very proud of the 200 games coming up. I have the opportunity to represent the Fremantle Football Club, my family and friends and my fiancée," he said.
"And to be able to play with Dean Solomon as well, who's been my best mate since we were 15 – is a dream come true.
"I hope [he comes back in]. We do need his toughness around the football and his body pressure and his strength. I think he'll come straight back in."
