SAINTS coach Kristian Woolf has explained why loose forward Morgan Knowles will be missing from the side on Thursday.

The Saints player of the year, who put in some thunderous tackles against Catalans Dragons on Saturday, has a knock from that encounter.

But Woolf explained that he will be fit for the derby with Wigan a week on Friday.

Woolf said: “He has just got a little bit of a niggle from last week.

“It is not a serious one and he will be back next week for Wigan, there is no doubt about that.

“But we just thought with the short turnaround it was a little bit risky this week.”

Saints have a number of back row options, with second row James Bentley back in the squad.

It could mean that Sione Mata’utia plays 13 with the versatile Jack Welsby once again jumping off the bench in that role.

Saints play Castleford on Thursday (7.45pm) at TWS.