New Zealand Warriors head coach Andrew Webster has provided an update on the health of veteran half Shaun Johnson, claiming the franchise is "confident" the 33-year-old will face the Knights on Saturday.

While Johnson and his bandaged calf were restricted to mere passing drills during the Warriors' training run on Thursday, Webster contended it was all part of the plan to nurse the veteran to game day.

The first-year head coach claimed that if Johnson could tick boxes during the Mt Smart side's final run on Friday, the fan favourite would face Newcastle in the do-or-die semi.

"If we he ticks the boxes tomorrow then he's good to go," Webster was quoted by

"He has just got to do parts of the captain's run. If he can't physically do it, he can't play. At this stage, all the signs are that he will physically be able to do it.

"That's why we've gone this far and that's why we're confident he will play.

"The best preparation for him was not to train today and keep the two days in a row loading out of it, to get him ready for [Friday] and to play."

Webster went on to confirm that Johnson had been hampered by his calf complaint since the Warriors' Round 27 win over the Dolphins.

And according to reports from Alex Chapman of NewsHub NZ, Webster was also willing to state that the veteran had, in fact, torn his calf.

While Webster's Warriors may yet be forced to do battle without Johnson, the former Panthers assistant was keeping his cards close to his chest in regards to any potential replacements.

"We're well prepared, we've trained without [Shaun], so we know what that looks like," Webster said.

"The Plan B everyone is going to have to find out... it'll be something that the boys are familiar with this week at training.

"The boys have done the reps, done the practice, so we're confident."

Should Johnson remain on the sidelines, it appears likely that Dylan Walker and Te Maire Martin will continue to steady the ship in the centre of the parkn after Ronald Volkman was left out of the 22.