It comes as the Knights joust to seal a preliminary-final berth without their own halfback Jackson Hastings, who has been ruled out with an ankle injury.
The favourite for this year's Dally M Medal, Johnson missed the qualifying-final loss to Penrith on Saturday with the training injury and in his absence the Warriors looked lost in attack.
Afterwards, coach Andrew Webster was confident the 33-year-old would line up in the Warriors' first home final since 2008 and most important game of the year.
On Tuesday, he named Johnson opposite Te Maire Martin in the halves to face the Knights but the Warriors will monitor their halfback through the week.
Webster had previously backed Martin and Dylan Walker to reprise their combination from the Panthers game if Johnson failed to recover.
"Knowing Shaun, he'll be doing everything he can to get on the field," Warriors legend and former teammate Simon Mannering told AAP.
"The way he's been playing, it will be a massive boost for the side if he's there."
In Sunday's elimination final, Hastings aggravated the ankle injury he suffered in round 24 and watched on in the second half as the Knights scraped past Canberra.
Adam Clune, who replaced Hastings between rounds 25 and 27, will partner five-eighth Tyson Gamble when the Knights conspire to force the Warriors out of the finals in straight sets.
Hastings has not been named in the extended squad so is no chance of making a late switch into the side, while second-rower Lachlan Fitzgibbon drops out with a shoulder injury.
Ahead of their semi-final against the Sydney Roosters, Melbourne have recalled Justin Olam for only his second game in eight weeks as they look to atone for a nightmarish qualifying loss to Brisbane.
Once rated among the best centres in the game, Olam fell out of favour with coach Craig Bellamy after the upset defeat to the Knights in round 21.
His only first-grade game since came when the Storm rested the majority of their best 17 in the week before the finals.
But after Melbourne battled to contain the Broncos on the edges last week, Bellamy has rolled the dice by banking on the 2020 premiership winner to return to his destructive best.
Young Tonumaipea drops out to make way for Olam, while Reimis Smith and Alec MacDonald come in for winger Xavier Coates (ankle) and fullback-turned-bench utility Ryan Papenhuyzen (ankle).
The Sydney Roosters have named a new-look back-line for that semi-final, with Paul Momirovski, Corey Allan and Jaxson Paulo coming into the side.
The changes follow injuries to Billy Smith (jaw), Joseph Manu (hamstring) and Joseph-Aukuso Suaalii (concussion) in the elimination-final victory over Cronulla.
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