Recently retired NRL star Paul Gallen was ruing the poor barrier draw for his horse Te Akau Shark who came from last to finish third in the Cox Plate at The Valley.

Te Akau Star ($17) drew the outside barrier in Saturday's $5 million weight-for-age championship with jockey Opie Bosson snagging the gelding back to the tail early.

Bosson rode his luck on Te Akau Shark and poked up on the fence to eventually finish third behind Japanese star Lys Gracieux and Castelvecchio, beaten 3-1/2 lengths lengths.

Te Akau Shark is the first horse Gallen has had a share in and the Cronulla Sharks and the NSW State of Origin-winning captain was delighted with Te Akau Shark's performance.

Gallen said he was able to soak up the atmosphere of Cox Plate day, but more importantly enjoy it.

"They're two different sports and I'm pretty relaxed with this one," Gallen said.

"I can probably enjoy it a little bit more without having any pressure on me.

"It (racing) is not something I understand too much but it's pretty cool coming down here to Melbourne and being part of the day."

Gallen thought Te Akau Shark had no chance of featuring when so far back at the half-way point of the race.

"But then it opened up on the inside there a bit and he started to come through and he came home like a steam train," Gallen said.

"Probably that wide draw hurt him having any sort of position after the start, but to finish off like that was awesome.

"To get a place in the Cox Plate, it's pretty cool."