THREE reasons why Exeter Chiefs should not be underestimated on Saturday.

Alistair Murdoch, Dave Sims and Tony Yapp return to Sixways with an Exeter side determined to dent Worcester's National One challenge.

Of course, you get used to the odd player returning hoping to make an impact on his old stamping ground. But three ex-players in one team!

Make no mistake the three are desperate to prove to John Brain and Andy Keast that they were hard done by when their contracts were not renewed in the summer.

Murdoch, a former Worcester skipper, is now back in his favoured centre position with Exeter and after a flying start to the season, the Australian is expecting to make a big impact on Saturday.

"All three of us have talked about it," said Murdoch.

"Obviously we are pretty keen to have a win up there at Worcester -- we've joked about it really.

"It was very disappointing not to have my contract renewed and that goes for me, Tony and Dave. But that's rugby, you've got to move on and I'm happy at Exeter now.

"The extra motivation is that we are playing one of the two top teams in the division. When you play Rotherham or Worcester, every team wants to knock them off their perch and that's how we feel now. It's funny in a way to be on the other side of the fence!"

Having seen Worcester's main promotion rivals -- Rotherham -- at close hand after a recent defeat in South Yorkshire, Murdoch is in the best position to sum up just where the leaders are in comparison to Worcester.

"Rotherham are solid, I'm not sure whether they've improved from last season. Their pack is maybe better and their back-line is as consistent as ever. They are a good side, they put 30 points on us in pretty quick time up there and it was a big haul to get back into the game.

"I think again that it will come down to Rotherham and Worcester for the title."

Certainly Brain and Keast are well aware of Exeter's quality and admit that if they were in the trio's shoes, they would want to prove a point.

"I think they'll all want to prove something to us," said Brain.

"All three of those players were at Worcester for a while, not just five minutes. Alistair is a former captain, Dave was the supporters' player of the year and Tony was a big crowd favourite.

"I think their presence on the pitch gives the game an extra edge. All three players wanted to stay at Worcester and we decided not to keep them. If I was in their position I would be wanting to stick that decision where the sun doesn't shine!

"On the flip side, I would like to think that Martin Morgan against Dave Sims, David Officer versus Alistair Murdoch and Craig Chalmers against Tony Yapp, in those cases that our players will want to prove that they are better players and we were right to have faith in them."

"Those three were favourites here and we emphasise, were," added Keast. "We hope on Saturday that the only time they get a pat on the back is in the bar afterwards. We want our supporters to get behind our players not former stars. If you want to move forward, you cannot look back in sport and live in the past.

"We are not worried about them, what we are concerned about is the team's performance on Saturday."