Somerset have added another impressive A-list player to their Twenty20 ranks with the signing of South Africa all-rounder Albie Morkel.

The 30-year-old will arrive in place of his compatriot Roelof van der Merwe, who may fall foul of United Kingdom work permit restrictions, as Somerset's second overseas player for this summer's Twenty20 Cup.

The Cidermen had already secured the services of West Indian superstar Chris Gayle for the competition as they look to end a run of three successive losing finals.

A left-handed batsman and right-arm medium-fast bowler, Morkel is an impressive performer in all formats of the game. He played in four out of five matches in the recent one-day series between South Africa and Sri Lanka.

In total he has played one Test match, 55 one-day internationals and 31 Twenty20 matches for the Proteas.

Somerset's director of cricket Brian Rose said: "Albie is an immensely gifted cricketer and an especially exciting one-day player, and fits in well with our set-up in the T20. The combination of Gayle and Morkel is a mouth-watering prospect for our supporters."

Originally, it had been planned that Van der Merwe would join Somerset as an overseas player from June 1 onwards, which would incorporate the Twenty20 competition, and remain for the second half of the season, but this is now unlikely.

Rose said: "As we went through the paperwork, it became apparent that Roelof was unlikely to be granted a work permit due to current Home Office legislation, though the door remains open for him at Somerset if the situation can be resolved."