The youth-driven Lightning was rocked with second half ankle injuries to inspirational captain Danni Stewart and goal keeper Jess Griffin, forcing coach Joy Grubb to blood teenagers Morgan Bennetts and Erica Schippers.

The absence of the injured leaders was the undoing of the Lightning, who suffered a nail-biting one-goal loss to Yarra Valley Grammar Ariels in a game at the State Netball and Hockey Centre last Wednesday night in which they entered as hot favourites .

"Unfortunately, it was a nail-biter most of the game and then we lost out captain and goal keeper," Grubb lamented.

"We had to reshuffle everywhere and it threw the whole team out."

The Lightning will enter this week's blanket bye in fifth place after seven rounds.

It has been a rollercoaster ride for the west's best with three wins, three losses and a draw.

The week's rest could not have come at a better time for the Lightning, who are sweating on the fitness of their two injured stars.

Stewart and Griffin are rated only a 50-50 chance to return for what could be a season-defining game against the Geelong Cougars on May 5.

"It's a critical game," Grubb said. "It's getting a bit serious now. We really need to win against Geelong."

Goaler Sophie O'Shea is in tip-top form.

One of the more experience players in the line-up at 22, O'Shea posted 31-from-34 in the 49-48 defeat to the Ariels to be the Lightning's most potent threat in the circle.

Victorian Netball League

Championship: VU-Western Lightning 48 lt Yarra Valley Grammar Ariels 49.

Division 1: VU-Western Lightning 27 lt Yarra Valley Grammar Ariels 45.

19 and under: VU-Western Lightning 22 lt Yarra Valley Grammar Ariels 48.