THREE key Castleford players will undergo late fitness tests before coach Gary Mercer can finalise his side for Sunday's Super League clash against the Giants at the Galpharm.

Prop Nathan Sykes, back-rower Michael Smith and half-back Jon Hepworth are all struggling with niggling injuries.

Mercer is confident the outcomes will be positive, although he does now have several new options open to him.

Ready to return after a lengthy injury absence is former Huddersfield front-rower Paul Jackson (thumb), who would be a welcome addition to the line-up.