WORCESTERSHIRE fast bowler Matt Mason will be given a late fitness test before Wednesday's must-win County Championship match at Northamptonshire (10.30).

The County are taking a 13-man squad because of the potential withdrawal of Mason and the possibility that the wicket suits spin.

"It's just to cover our bases," said director of cricket Steve Rhodes. "The wicket might spin and Matt Mason's back is not quite right."

Worcestershire need to beat Northants and hope Essex, who have a four-point lead, don't take maximum points at Leicestershire if they are to win promotion to division one.

But Rhodes believes there is no need for him or captain Vikram Solanki to rouse the troops beforehand.

"They won't need me or Vikram to motivate them," he said. "It will be a case of relaxing them. You can't win a four-day game on the first day.

"Just like in a one-day game, you think of winning sessions and the processes that are needed to win sessions.

"It will be a case of getting ourselves into a winning position. We know that, if we win, the pressure will be on Essex.

"We won't be worrying about what Essex are doing. We can't do anything about that."

Worcestershire have already won promotion from division two of the NatWest Pro40 League after Surrey suffered a surprise defeat against Somerset on Sunday and Rhodes believes it could give them a big lift going into today.

"On Saturday we were distraught but sport is a strange thing. It was a big boost for the team when Somerset turned over Surrey 24 hours later.

"It makes the week even more enjoyable and I'm sure the lads will go into the game full of confidence."

Rhodes knows it won't be easy against a Northamptonshire side who are starting to come into a bit of form.

He has identified South African all-rounder Lance Klusener as the dangerman.

He is also keen to keep Chris Rodgers, David Sales and Usman Afzaal quiet and is aware of the danger posed by England left-arm spinner Monty Panesar.

Rhodes added: "It will be interesting against Panesar if the wicket does turn."

Worcs (from): Vincent, Moore, Solanki, Smith, Hick, Davies, Batty, Sillence, Kabir, Price, Mason, Zaheer, Malik.

Northants will be without seamer Matt Nicholson who has a knee injury and is returning to Australia to ensure that he is fit for the start of the domestic season.

Nicholson's place is taken by former Worcestershire pace bowler David Wigley.