PORT Adelaide has suffered a blow with draftee Sam Hayes rupturing his ACL at training on Tuesday.

The first-year ruckman, who turns 19 on Saturday, will undergo surgery and miss the remainder of the season.

The Power's general manager of football Chris Davis said Hayes sustained the injury during a training drill.

"It’s really unfortunate for Sam," Davies said.

"He felt some pain in his knee after landing in a marking contest and scans have confirmed he tore the ligament.

"The fact he’s come such a long way this year, from a physical perspective, is testament to the work he’s put in since arriving at the club.

"I know he’ll attack his rehabilitation with the same discipline he has applied to his training, which will give him the best opportunity to be back early in the 2019 season."

The Power selected the dual All Australian under-18 ruckman with its first pick (47th overall) at the 2017 NAB AFL Draft.

Hayes is the second Power player to have ruptured his ACL this year after half-back flanker Hamish Hartlett tore his at the end of April.

Earlier this year, Hayes signed a two-year contract extension with the Power until the end of 2021.