Saracens are primed to face another breakdown master when they seek to build on a perfect start to their Gallagher Premiership title defence at Northampton tomorrow.

A week after seeing Bristol's veteran Australian openside George Smith rule the floor at Allianz Park, director of rugby Mark McCall knows former South Africa flanker Heinrich Brussow will offer a similar threat.

Smith was sent off for a dangerous tackle in the third quarter, enabling the champions to storm clear, but he had already left a major impression on McCall that will also be felt at Franklin's Gardens.

"George Smith's was one of the best individual performances I have seen for a long time," McCall said.

"We knew how good he was and we knew what was coming, but we still didn't deal with him at all well. He was magnificent while he was on the field.

"Heinrich Brussow is also a high-class player and a very similar kind of player to George Smith.

"When players like that get over the ball, it's over - it doesn't matter how hard you hit them.

"We must make sure we are in control of that and be urgent at the breakdown. There are a lot of things we have to get right which we didn't get right last week."

Eddie Jones will be present at Franklin's Gardens to see a number of his England players on the comeback trail.

Saracens number eight Billy Vunipola makes his first start since re-fracturing his arm against South Africa in June while lock George Kruis features on the bench having recovered from ankle surgery.

Owen Farrell is absent, however, due to an injury only described by the club as a "minor strain", so Alex Goode is selected at fly-half.

For Northampton, Dylan Hartley's return from a concussion-enforced break from the game gathers momentum in the form of his first start since March as Saints look to build on their first win under new boss Chris Boyd.

"It feels like a completely different club. We've drawn a line under the past," Hartley said.

"There's an enthusiasm around the place and the buy-in from everyone in the playing group has been unbelievable.

"It's a truly exciting environment to be in and we're still in our infancy in terms of what we want to do as a team.

"Last season was a particularly sour one and there are a lot of wrongs that we want to put right as a team."

Alongside Saracens, Exeter are the only other team possessing a maximum 10-point haul after two rounds and their title challenge continues against Sale with Jack Nowell restored on the wing.

Bath go in search of their first win of the season at Harlequins while the league's bottom two teams - Worcester and Newcastle - do battle at Sixways.