Bath and Northampton put unbeaten records put on the line at The Rec BATH and Northampton will put their 100 per cent Aviva Premiership records on the line in tonight's clash at the Recreation Ground. Saints head to the west country following victories over Gloucester and Exeter, while Bath defeated Worcester and Wasps in their opening two Premiership games. "Bath will be a big challenge," Northampton rugby director Jim Mallinder said. They have started the season very well. They came from a long way behind and held their nerve to win at Sixways while, against Wasps last weekend, they put together some dangerous attacking moves. The Rec is always a tough place to play. The fans are right on top of you and it can be intimidating for visiting teams and it is up to us as to how we respond. At times in our first two games we have played well and scored some good tries, but we have also been guilty of not finishing games off, and this is something we will be looking to improve. Mallinder has made four changes from the team that edged out Exeter 24-21 last Sunday, with one of them enforced. South African No 8 Gerrit-Jan van Velze is serving a four-week ban after being cited for a tip tackle on Exeter scrum-half Will Chudley. Van Velze admitted the offence at a Rugby Football Union disciplinary hearing earlier this week and he must now sit out Premiership games against Bath, Worcester, Wasps and London Irish. Former Wales back-row forward Rhys Oakley will fill his role, while the other changes see centre Luther Burrell replacing George Pisi, stand-off Stephen Myler in for Ryan Lamb and prop Tom Mercey taking over from Brian Mujati. Bath, meanwhile, show two changes, with Ben Williams replacing injured centre Matt Banahan and Wales prop Paul James starting instead of Nathan Catt. "Northampton are a very strong side, who have made a good start to the competition," Bath head coach Gary Gold said. We all know about their strength in the forwards, but they also back that up with some hugely skilful backs who can attack from anywhere on the field. We were pleased with the performance against Wasps but we know there is still more we can do to improve and we have been working hard on this. Tomorrow's winners will go top of the Premiership, although it is likely to be a short-lived stay. Reigning champions Harlequins, who are at home to winless Sale Sharks tomorrow, and Saracens or Leicester - they clash at Wembley Stadium this weekend - can claim pole position during the Premiership campaign's third weekend.