Greg Blewett, the former Australian batsman, is set to sign for Surrey this Friday in time for this season's Twenty20 Cup. He will replace Saqlain Mushtaq, the Pakistani offspinner, who will miss the rest of the summer with a knee injury.

Blewett, 32, scored centuries in each of his first two Tests against England in 1994-95, and has been sounded out as a replacement overseas player. With Azhar Mahmood also out through injury, Surrey are eager to shore up their squad ahead of the tournament, which they won in its inaugural season last year.

"We've looked around for a spinner but there aren't many around," said a Surrey spokesman, "especially as the Asia Cup is about to start." They also signed India's Zaheer Khan as an amateur for two matches, although he was not 100% fit either.

Blewett, who played the last of his 43 Tests in New Zealand in March 2000, has previously played for Yorkshire, Nottinghamshire, Middlesex and Kent.

Saqlain, who has played 49 Tests and 169 one-dayers for Pakistan, only managed three first-class matches this season, the last of which was in mid-May. He has been at Surrey for the last seven summers, but may be coming towards the end of his time at The Oval after a disappointing time last season, taking 41 wickets at an average of just over 33.