The former Tottenham, Liverpool and Leeds United striker produced his cartwheel and roll on two occasions on the weekend as the Galaxy beat Seattle Sounders 3-0 in the Western Conference playoff first leg with Arena turning critic on his star scorer.
"When he was younger there was a lot more elevation. It was almost a flip in the air," Arena said. "This is a tumble on the ground so there's less chance of injury at this point in his life."
But Arena was quick to point out that as long as Keane is doing his job, it doesn't really matter what else he produces on the pitch.
"But at the end of the day, he does what other people can't do on a regular basis: score goals," he added.