Wigan Warriors winger Dom Manfredi has been ruled out for the rest of the Super League season with a knee injury.
The 22-year-old sustained the injury following a heavy challenge from Rangi Chase in Friday's 36-22 defeat at Castleford Tigers and scans have revealed anterior cruciate ligament damage.
Manfredi, who made his debut in 2013 for Wigan, signed a four-year deal with the Super League club in April 2015.
The winger was fourth in the Super League scoring chart in his first full season in 2015 and had scored 14 tries in 21 appearances this year.
"Dom's out for a long time," Wigan coach Shaun Wane said. "I'm gutted for him.
"He will bounce back stronger and the players are very motivated to get something from the season for him."
Wigan also have doubts over fellow winger Josh Charnley and stand-off George Williams for Friday's derby with St Helens after they also picked up knee injuries at Castleford.
"We'll check on them closer to the end of the week," Wane said. "We don't think they're serious but they couldn't train today.
"That's the story of our year, we've never had a full team training, so it's something we've become accustomed to. We'll still be putting 17 really competitive players out on Friday."