Johnson initially appeared to be in grave doubt for the anticipated clash in Wellington after leaving last week's loss to Melbourne in a moon boot.

However, Sharks teammate Aaron Woods was optimistic about Johnson's chances of playing after the team flew across the ditch on Tuesday night.

"Shaun had a little run (on Tuesday). He didn't run with the side but he had a run on the sidelines with our medical staff," Woods told Sky Sports Radio.

"He's just rolled his ankle and it swelled up a little bit after the game. Obviously we had to fly from Melbourne then had to fly here to Wellington.

"So far he's looking okay. I think he will play, but he's still got to go through all the protocols throughout our captain's run."

Johnson's form has come under the spotlight during the Sharks' four-game losing streak, which has resulted in the club tumbling out of the top eight into ninth.

But the New Zealand international showed glimpses of his best with a try and try assist in their heavy defeat to the Storm last week.

"I thought he had a really good game on the weekend. He was really damaging with the ball," Woods said.

"He did cop a fair bit in the lead-up in the week. It was exciting to watch him play.

"I know he's so excited and hopefully he can get out there on Friday night."

Sharks coach John Morris has made three changes to his side for the crucial encounter following injuries to Josh Morris (nose) and Josh Dugan (hamstring).

Matt Moylan (hamstring) and co-captain Paul Gallen (glute) return from injury, while Scott Sorensen comes in for the axed Jayson Bukuya.

Kyle Flanagan is expected to be called up from the extended bench should Johnson fail to overcome his ankle issue.

Australian Associated Press