Somerset are likely to be without Alviro Petersen for the first game of the Championship season.

Petersen, who has signed as club's overseas player for the first part of the season, has been detained in South Africa to complete fitness tests for the national board. He will fly on Tuesday night and arrive in London on Wednesday morning, leaving little time to complete the necessary formalities and travel to Chester-le-Street for the match against Durham.

"He will arrive in London on Wednesday morning," Dave Nosworthy, Somerset's new director of cricket told ESPNcricinfo, "so it's unlikely we can get him through customs and up to Durham in time."

Petersen's absence is a blow to Somerset. They are already without Nick Compton, who is being rested on the order of England following his impressive efforts for England over the winter, and hoped that Petersen could help plug the gap.

They do welcome back the seamer Alfonso Thomas, however, who had an agreement with the club to prioritise the Championship over any potential IPL contract. Somerset were second in the Championship in 2012, equalling their best-ever finish.

Warwickshire, last season's champions, are also set to be missing a key player, with Chris Woakes rested on the orders of the ECB. The allrounder is suffering from fatigue, so will not be available again Derbyshire. Keith Barker and Boyd Rankin are also out, with Dougie Brown, Warwickshire's new coach, confirming that Oliver Hannon-Dalby and 20-year-old Tom Milns will form the bowling attack alongside Chris Wright.