Somerset have signed South Africa all-rounder Albie Morkel for this season's Twenty20 Cup competition.
Fellow countryman Roelof van der Merwe had been expected to be Somerset's second overseas player for the tournament, alongside explosive West Indies batsman Chris Gayle, but potential problems over a work permit forced the county to change their plans and recruit 30-year-old Morkel instead.
Director of cricket Brian Rose told the club's website: "As we went through the detailed paperwork process it became apparent that Roelof van der Merwe was highly unlikely to be granted a work permit due to current Home Office legislation.
"The door remains open for him at Somerset if the situation can be resolved. In the event of Roelof being unable to gain Home Office clearance in time for this season, I will be actively looking for an overseas replacement for July, August and September."
Morkel - a left-handed batsman and right-arm medium fast bowler - has played one Test, 55 one-day Internationals and 31 Twenty20 matches for South Africa, as well as appearing in the Indian Premier League for Chennai Super Kings and the T20 in 2008 for Durham.
He has appeared in 157 Twenty 20 matches in his career and hit 2,285 runs at 28.20, including 128 sixes, as well as capturing 136 wickets at an average of 27.40.
"Albie is an immensely gifted cricketer and an especially exciting one day player and fits in well with our set up in the T20," added Rose.
"The combination of Gayle and Morkel is a mouth watering prospect for our supporters."