CHRIS Pearson is back in plaster just weeks after being passed fit.

The Worcester Rugby Club hooker has already missed six weeks of the season with a broken wrist and, after returning on the bench against Otley two weeks ago, the injury is still giving him trouble.

The South African has had a cast replaced in a bid to give the injury more time to heal. He is expected to be out of action for another two weeks and is now hoping to be fit in time for Worcester's trip to Orrell on February 16.

"It's very frustrating for Chris but if it helps him then it is better in the wider scheme of things," said coach Andy Keast.

"He was passed fit, he didn't come back too soon but he has been complaining that it was still painful. If all goes well then he should be ready for Orrell."

Pearson's absence is the latest in a long casualty list at Sixways and the second this week after James Ogilvie-Bull's damaged a/c joint on Monday night.

Meanwhile, the former British Lions coach has told his side defence is the key ahead of Worcester's showdown with Manchester. With Worcester and Rotherham slugging it out at the top of the National One table, Keast has ordered his players to keep the Grove Park team out on Saturday (3pm).

After a league and cup meeting so far this season, the clubs have already played one another twice with Worcester amassing 139 points. They have, however, conceded six tries against Manchester and Keast has warned his team that points difference could be vital come the end of the season.

"One of the main targets for Saturday is to not concede a try," he said. "It may come down to points difference and as much as we've been pleased with the points we've scored, we've been very disappointing with the tries we've conceded."

Craig Chalmers wins his first start since November after impressing during Worcester United's 40-13 win over a Plymouth development side on Monday. The former Scotland fly-half comes in for Tim Walsh.

The Australian may, however, be tried out as an outside centre during the second half in the wake of Worcester's injury list and the continued threat of a Gloucester recall for on-loan full back Chris Catling.

Craig Quinnell is named only as a substitute and faces a fitness test on a nerve injury in his bicep. Prop Neil Lyman is ruled out with a hamstring niggle.

Worcester: Catling; Ezulike, Roke, Trueman, Garrard; Chalmers, Swanepoel; Windo, Hall, Olver, Zaltzman, Gillies, Evans, Pfister, Jenner. Reps: O'Reilly, Brown, Walsh, Pearl, Davis, Morgan, Quinnell.