England assistant coach Marcus Trescothick says Andrew Flintoff is back to his old self after the former all-rounder's horrific car crash.

Flintoff had been out of the public eye since being in a serious car accident while filming for the BBC driving show Top Gear last December.

After a lengthy recovery, the 45-year-old was coaxed into joining England's backroom staff in an unpaid capacity earlier in September.

Trescothick was an England team-mate of Flintoff for several years and he is relieved to see his friend rediscover his boisterous personality after such a traumatic experience.

"He hammers me more than anyone else. I'm the first target for his banter at the moment but having him around has been superb, it really has. He's been brilliant," Trescothick told reporters on Monday.

"Seeing him grow back into Freddie, obviously he's been away from cricket for a long period of time but this is where it all starts and where it belongs for him. The guys have really taken to him.

"The couple of times he's spoken in the changing room it's been like 'wow'. You can see the difference and I've seen the progression of him as a character, the way he talks and delivers messages to players has been superb.

"To have him sprinkling a bit of gold-dust around the team and having the younger players working with that has been invaluable. You can't put a price on it."

Flintoff was initially enlisted for England's recent one-day internationals against New Zealand ahead of the 50-over World Cup in India in October.

But the former England captain, who memorably played a key role in his country's 2005 Ashes series triumph against Australia, has remained involved for the current ODI clashes against Ireland.

That three-match series concludes in Bristol on Tuesday, with an experimental England squad holding a 1-0 lead after their victory at Trent Bridge on Saturday.

England are resting the squad that will travel to India for the defence of their World Cup crown, offering fringe players a chance to push their case for more regular spots.

Teenage leg-spinner Rehan Ahmed is one of those emerging youngsters, impressing at the weekend with figures of 4-54 against Ireland.

"I like the way he keeps relishing opportunities and keeps doing the business," Trescothick said.

"As a younger player there's a lot more scrutiny on him. He comes into the Test team and gets five wickets (against Pakistan in December), he comes into this format and does well. Hopefully that carries on."