Chris Jack and Brent Russell will be pivotal to Saracens' quest for success next season, according to director of rugby Eddie Jones.

Jack, the towering All Black lock, became arguably one of the Men in Black's most high profile signings last summer while Springbok speedster Russell was given the task of filling Thomas Castaignede's shoes.

However, both imports arrived having played plenty of rugby for their previous employers while Jack also featured for New Zealand in their dismal World Cup campaign. Whether lethargy was a factor both were hit and miss for Sarries last season before injuries curtailed their involvement.

However, Jones believes the former international duo will be different animals next season following a well earned rest over the summer.

"Those guys have been playing constantly since January 2007 - 18 months is a long period," said Jones, speaking to the Watford Observer from South Africa earlier this week. "They are now playing in a new competition for a new team. You were never going to see the best of them (last season), that is the reality of it."

Ex-Crusaders second row Jack enjoyed an immense first team debut, albeit against poor opposition, in the 71-7 Heineken Cup hammering of Viadana last December, the game where Russell also made his bow. Jack plundered two tries in the stunning win over Biarritz at Vicarage Road before the 29-year-old's season ended abruptly when he damaged tendons in his hand during Sarries' 30-3 EDF Energy Cup semi final defeat to Ospreys in March.

Russell, 28, has also endured his fair share of bad luck. He suffered a broken collarbone in a freak pre-season training ground accident before a torn hamstring in the Heineken Cup win over Ospreys forced him to miss the season run-in. The former Western Province star scored five tries in 16 appearances but he should eclipse that total with ease next season.

"They are now having a good break and will be fully fit when they come back to us," added Jones. "Both have the talent and ability but we've got to motivate them. If they are both comfortable in their roles there is no reason why they can't be outstanding and influential for us."

Both will feature in Sarries' pre-season schedule which starts with a trip to Bayonne on August 8. A scratch side will take on Australian Super 14 outfit Western Force on August 12 before the senior team pit their wits against the touring side three days later. Both games will be played at Old Albanian RFC.

Jones is then expected to field a strong side in the Middlesex Sevens at Twickenham on August 16 with a view to winning it for the first time before the senior team travel to Rodney Parade to take on Newport Gwent Dragons on August 22.

"Bayonne is a good first game for us," commented Jones. "Their ambitions are not too dissimilar to ours in that they have fallen just short and want to go forward and be up there. Western Force have played under the new ELVs (Experimental Law Variations) and will be a good test while Gwent will be a tough encounter.

"There will be a number of things in terms of how we will be playing to try out. There will be competition for places and these matches will give everyone in the squad the chance to put their best foot forward."

Jones will give youth a chance next year with the likes of Alex Goode, Mickey Wilson, Noah Cato and Andy Saull hoping to follow Don Barrell and Adam Powell in to the first team.

"It's going to be a great challenge for the younger guys who I have high hopes for," continued Jones. "They are all good players and how far they progress will depend on how hard they work at their game.

"Pre-season will show how desperate they are to make it. They are all very talented but talent only gets you so far - consistent application will determine whether they make the first team or not."

Meanwhile, Jones has raided Bath for the services of Scott Murphy, who becomes the Men in Black's new strength and conditioning coordinator.

Prior to his four year stint with Steve Meehan's side Murphy enjoyed success within the Australian olympic coaching team as a track and field coach.