St Kilda coach Brett Ratten says forward Jack Hayes will be offered a new contract "as soon as possible" after the mature-age recruit suffered an ACL tear in his side's 17-point win against GWS.
Hayes' left knee gave way late in the first quarter in Canberra on Friday. He hobbled from the field and played no further part, with the injury quickly determined to be a suspected ACL.
Ratten said the brutal injury meant they left the contest with mixed emotions after reeling off a fifth straight win.
"We came to Canberra to win the win the game ... I thought our second half was very, very encouraging," he told reporters.
"And then when you have somebody like Jack Hayes - what a great person, what he's done in a short term at our footy club - to do an ACL, the mood is a little bit up and down.
"Jack's a great introduction to our footy club with the way he's gone about it.
"He'll have the ACL treatment and recovery and he'll be at our footy club for a long time."
Asked if Hayes, who only signed his one-year rookie contract in March as a pre-season supplemental pick, would be offered a new deal, Ratten said it was a clear priority.
"We want to take away any of the anxiousness and allow him to go into this rehab process knowing what the future looks like," he said.
"He doesn't have to worry about that and he can just get to work and do what he does ... we'll look after him."
It dampened the mood after the grinding win, where the Saints held their own at the contest in the second half despite Josh Battle being thrown into the ruck as Rowan Marshall battled a leg injury.
While Marshall remained on the field up forward, Battle impressed with 23 touches and 10 marks.
"He has the capabilities to play multiple positions and he's a great runner," Ratten said.
"So with that we've sort of tested the water a bit and swung him there, but it doesn't give him any real clarity on what his role is.
"The players had to dig in, we were down a man really ... they had to dig in and find a way and play in different spots and do different things for the team and I thought that was very encouraging."
