"I feel blessed that he came to the Phoenix when he did or this might not have happened.
"He sat me down and told me it isn't acceptable not to be disciplined on the field, and you don't see me giving away silly free kicks round the box these days or getting cheap yellow cards.
Merrick said he was pleased Sigmund had decided to continue and suggested there was no reason next season had to be his last.
"Ben is becoming, if he isn't already, a legend at the Phoenix and is an iconic character," the coach said.
"He feels he has never been the most skilful of players but he always gives 100 per cent and is very coachable.
"They say you can't teach an old dog new tricks but Ben has proved that saying wrong.
"His passing into midfield and to the front players has improved out of sight, and in the game against the Mariners at Eden Park he had a 90 per cent success rate.
"The partnership he has formed with Andrew Durante is formidable and very important to the team."
Sigmund made his debut for the Phoenix in 2008 and has made 154 appearances for the club.
