A STINT in the reserves has helped Sydney defender Jared Crouch get his football brain working again.

Crouch acknowledged his own form had been poor following his long-awaited return from injury in round four.

He was dropped from the senior side last week, when the Swans' leadership group made the team selection. He said he did not resent the decision.

"I was under no illusions. My form wasn't good enough. I just needed to go back and work hard in the twos," Crouch said on Tuesday at the SCG.

"[The leadership group] realise if I'm up, playing my best football, I can certainly make a difference to the side, but if I'm not, I'm certainly hurting the side.

"The easy option may have been to just stay in the seniors, but we took the option to get into the reserves. I probably was hurting the senior side."

It was not Crouch's body that let him down, despite the numerous injuries he endured last season. Nor was it a fitness problem, though his pre-season was disrupted.

Crouch's problem was simply that he had not played enough football since his injury.

"It's certainly not a physical thing," he said. "It's not the way I'm running or even how I'm using the football.”

“It's making sure that I'm reading the play a bit quicker than what I have been, which I guess you just lose when you miss a great deal of football."

"Even leading up to the four games I did play, I only played one or two [practice] games. I guess, in hindsight, I should have played a lot more football and made sure the brain was working as much as the body was."

Crouch will join teammate Tadhg Kennelly in running the prestigious New York marathon in November, in an attempt to raise money for the Heart Foundation.

It’s a cause close to Crouch’s heart after the death of his close friend and Swans' trainer Wally Jackson, who suffered a heart attack at a Swans match in 2004.

"Unfortunately, heart disease [and] heart attacks have affected us all here at the Swans," Crouch said.

"It's going to be a great challenge for the both of us, but it's all about raising money for a great charity and getting the awareness out there for the general public."

Crouch's partner, Rebecca, will also be running the marathon, which he believes will provide the perfect back-up plan.

"Worst case scenario: we're going to get one of those twin prams. We're going to sit in front of it, and Bec's going to walk us around the 42 km marathon, so we do have a fall-back plan if we can't run it."