"Des has been fully supportive of it since day one, it's always been the planned transition ... it's just come a bit earlier than expected," he added.
Toovey, who captained the Sea Eagles to the 1996 premiership and two other grand final appearances, said he was excited about coaching the club he played 238 matches for.
"I'm very excited, I'm a local bloke," he said.
"Making first grade in itself was a wonderful achievement and what we all aspire to as local juniors, now to transfer into that coaching role is the next level and hopefully I can be as successful as Des was."
Toovey was non-committal on speculation that former Manly teammates Cliff Lyons and Steve Menzies would form part of his coaching staff.
"It's too early, everyone's got Chinese whispers out there everywhere. I've got a year to transition into the role. We'll be putting those things in place over the next six to 12 months."
Toovey has received player support with star five eighth Kieran Foran saying he's the best man for the job of replacing Hasler.
"He's been there since 2004 under Des, he's learnt the ropes," Foran said.
"He's an ex-player at the club, he's won comps for the club. He is a very passionate guy and knows what it is about."
- AAP
