SARACENS centre Ben Johnston had admitted it was a tough decision to leave Saracens for Northampton Saints at the end of this season.

The 28-year-old says he was impressed by Saints head coach Paul Grayson's future plans for the club, but said it would be a wrench to leave Sarries after nine years.

Johnston said: "Having spoken to Grase and seeing what he wants to do with the club, I think now is a good time to get on board.

"It was a pretty tough decision, as I have been at Saracens so long, and it was certainly not one I could make overnight. But now I have made that decision I am looking forward to establishing myself at Northampton."

Johnston joined the Men in Black from Waterloo in 1998 and has gone on to make 178 appearances for the club.

He played the first 10 games of the current season before undergoing surgery on a groin injury he picked up at Gloucester last November.

Saracens Director of Rugby Alan Gaffney said: "Ben has taken a decision based on what he feels is best for his rugby career and his family and we have to respect that.

"He had a strong start to the season with us but the surgery in early November on a long-standing injury has meant he's been ruled out of action since then. He is still working on his rehabilitation and we hope to see him back in action next month.

"He's been with Saracens for eight seasons and has been a very good servant to the club. We wish him all the best for the future. He is someone who we will miss but we do have cover in other areas of the squad."

Saints coach Grayson is delighted with his new aquisition.

"We have been hit hard with injuries in the centres leaving David Quinlan to fight on alone for almost two seasons," he said. "Ben is an international class 12 with ambitions to push himself forward for further international recognition. He is physical, quick and can play at 12, 13 or on the wing. He provides excellent strength in depth in all these positions."