SPEED king Tom Richardson has been given the job of shooting down Exeter Chiefs' Twickenham dreams.

Worcester Rugby Club's pace ace is named in the side to face Ian Bremner's men in Saturday's Powergen Shield semi-final clash at Sixways (3pm).

Richardson replaces Nnamdi Ezulike who is rested, but director of rugby John Brain has refused to ring the changes from Saturday's victorious National One team.

"We've given Tom an opportunity," said Brain. "Nnamdi is rested but Tom has done very well for us this season when he's been given a chance. He is a very quick player and we hope that will cause Exeter a few problems."

David Officer continues his comeback from an ankle injury following an impressive run-out against London Welsh on Saturday, while Martin Morgan comes in for the rested Dan Zaltzman at lock. Eighteen-year-old lock James Percival has been added to the bench alongside fit-again fly-half Craig Chalmers.

Tim Walsh and Christian Evans (hamstring), Gary Trueman (ankle) and Mark Gabey (arm) are still not fit but will all be available for Worcester's March 15 clash with Plymouth.

"We want to remain unbeaten at home this season," said Brain as he looked ahead to Worcester's third meeting with Exeter this campaign.

"It's an opportunity to play against a good side at home and after this game we only have one match at Sixways before Rotherham."

If successful on Saturday, the Warriors would book a final place at Twickenham on April 5 against either Rotherham or Orrell. Good news for the supporters but, with the all-important league showdown with Rotherham on April 12, the management could be forgiven for not wanting the added worry.

Brain, though, is adamant that he has a responsibility to take the Exeter tie seriously.

"We will cross that bridge when we come to it," he said. "We are not going to throw a game at home against a side like Exeter. We cannot treat it lightly or give any indication that it is OK to lose the game. It is important for us to stay unbeaten at home."

Warriors: Roke; Richardson, Officer, Wigram, Garrard; Brown, Swanepoel; Windo, Hall, Lyman, Morgan, Gillies, N Mason, Nias, Jenner. Replacements: O'Reilly, Southwell, Chalmers, Olver, Pearl, Percival, Pfister.