YORK City Knights are hopeful star centre Jake Butler-Fleming's latest injury is not as severe as first feared - giving him chance to finally have a proper impact on their promotion challenge.

The on-loan Aussie, on his return from a dead leg, exited Sunday's Betfred League One loss at Whitehaven inside five minutes after tearing a pectoral muscle.

An ultrasound scan has confirmed a tear but the indications are it is not a season-ending one. He will now go for an MRI scan to detail the severity of the injury but head coach James Ford is optimistic the 26-year-old former Penrith Panthers junior will be back in action in July, in time for the business end of the season.

"He's had an ultrasound scan," said Ford."There is a tear but seemingly not as severe as we had feared.

"He's going for an MRI to check that is the case. If so, we're hoping to have him back playing in six weeks.

"To have a player of that calibre come back would always be a boost.

"That (being out for the season) was the worst-case scenario but we were hopeful it was not that and we're pleased it appears not to be."

Butler-Fleming, after playing five times for York on loan from Hull KR last season, including scoring a debut try in the memorable win over champions-to-be Toronto Wolfpack, signed a permanent deal with the Knights over the winter only to leave on the eve of the season having been offered a full-time contract by the Canadian outfit.

He made that switch for an undisclosed fee but played only once for the Wolfpack, plus twice on dual-reg for Bradford Bulls, before returning to York in April on loan for the rest of the season.

He played only three times, however, before a dead leg suffered in the win at Hunslet ruled him out for the next two matches prior to the trip to Whitehaven.

As he is still contracted to Toronto, the Knights are liaising with the Wolfpack regarding his medical treatment.

Knights chairman Jon Flatman said: "We obviously want Jake back on the field as soon as possible and we thank Toronto for all their support."