A bizarre lawn bowls injury has cost Brodie Croft a chance to press his claims for Melbourne's No.7 jumper as the Storm prepare to welcome back a host of big names for their first finals hit-out.

Melbourne went down to Penrith 22-16 on Friday night with the likes of Billy Slater, Cameron Munster and Nelson Asofa-Solomona all absent, though Croft's game-day withdrawal ranks among the strangest seen in rugby league for some time.

An inflamed bursa – a small fluid-filled sac – in Croft's knee was exacerbated by the sedate pursuit of lawn bowling throughout the week, with rookie half Scott Drinkwater only called in as his replacement at 1pm on game day.

"It wasn't done through the lawn bowls, but the continual bending of (Croft's) knee in lawn bowls has inflamed it and I've never seen a knee so swollen on Thursday," Storm football manager Frank Ponissi told NRL.com.

"It was like a balloon so they drained it, hoping that overnight it would come down. It did, but not enough and after we took him for a run at midday he wasn't up to playing.

"If it had been a Saturday game he probably would've been right. He'll be back at training Monday, it's just the swelling didn't come down enough for that game."

Match Highlights: Storm v Panthers - Round 25, 2018

Missing out on the final round clash with Penrith will likely cost Croft his starting spot given Slater (compassionate leave) and Munster (knee) are certain to return to the backline, with playmaker Jahrome Hughes set to switch into the halves at Croft's expense.

Touted as Cooper Cronk's long-term replacement at the scrumbase, Croft's latest frustrations cap an up-and-down year for the youngster, who has jostled with Hughes and Ryley Jacks for a starting halves gig throughout 2018.

With another unidentified Storm player nursing a stiff back because of his golf swing, Munster joked on Channel Nine that Craig Bellamy would ban extra-curricular throughout the finals.

Ponissi could at least see the irony in Croft's misfortune.

"We're always telling our players to get off social media and get off their computer games, and it's not like Brodie was skateboarding or doing anything high risk, Ponissi said.

"He's gone lawn bowling so we're not giving him too much grief. I've never seen anything like it, it's just a strange one that comes when we've got a few injuries."

As well as Munster and Slater, flying Fijian winger Suliasi Vunivalu will also push to return from a hamstring injury in week one of the finals.

Melbourne's loss to Penrith has opened the door for the Roosters to pinch the minor premiership, but either way the Storm will be hosting a home semi-final against either the Rabbitohs or Sharks depending on results.

Both Vunivalu and back-up rake Brandon Smith (knee) are expected to train with the Storm's main squad this week and push for inclusion, while Nelson Asofa-Solomona is another week away.

"Suli's more a chance of playing than not playing," Ponissi said.

"He had a good run on Saturday, he's a chance of getting back into full training by mid-week, but he's not certain at this stage."

Meanwhile NRL.com understands that Drinkwater, who had been on Newcastle's radar earlier in the year, has agreed to a two-year extension with the Storm.