Newcastle Knights have been dealt a cruel blow with scans revealing Kalyn Ponga and Dylan Brown are expected to be sidelined for an extended period. 

The duo were both injured during their side's win against the Manly Sea Eagles at Brookvale on Sunday afternoon.

Ponga is expected to miss 6-8 weeks with a high-grade hamstring strain, while Brown will miss four weeks for a moderate MCL injury.

Ponga reached for a hamstring when he finished off a long-range try for the Knights, where he linked up with Bradman Best.

He was then sent down the tunnel in the next set after being unable to move freely.

Not long after Dylan Brown made a break and was tackled by Tom Trbojevic, where he injured his MCL and was shortly ushered off the field.

In good news, Fletcher Sharpe is expected to return from an PCL injury sustained in Las Vegas in Round 1 next week against the New Zealand Warriors.