Somerset are already closing in on a short-term replacement for Alviro Petersen, after the South African was called up to his country's ICC Champions Trophy squad.
Petersen was initially left out of the South Africa party for the tournament that will take place in England and Wales from June 6-23.
But the injury to former Somerset captain Graeme Smith has opened the door for the 32-year-old, who has been in fine form for the county.
Somerset expect him to be with his national team from May 27 to June 24 – although he may return earlier if the Proteas are eliminated from the competition before the knockout phase.
However, as a minimum, the top-order batsman will miss Somerset's LV= County Championship matches against Yorkshire and Durham, and their YB40 games against Glamorgan, Middlesex, Unicorns and Leicestershire.
If South Africa reach the latter stages of the Champions Trophy, he could also miss Somerset's Championship game at Derby, which begins on June 21.
Petersen has scored 495 Championship runs at an average of 82.50 this season, plus 42 from 38 balls in his team's YB40 win at Yorkshire.
Somerset have taken a proactive approach to Petersen's imminent absence – and started to search for a replacement even before they received confirmation of their in-form batsman's call-up.
Somerset director of cricket Dave Nosworthy said: "We are very pleased for Alviro. It was never his intention to be leaving us, but he has played very well for Somerset and this opportunity is a just reward for him.
"This chance has arrived out of nowhere, and we are pleased for him, even if we are disappointed for ourselves, if we were to be selfish.
"We had a bit of a heads-up, so we had already been on track with regard to a Plan B – and we are pretty close to finalising a replacement, which would be for a month while he is away.
"Hopefully we can announce that player in the next 24-48 hours. It has been difficult to try to find people, because the IPL is still going and the Champions Trophy will soon be in full swing.
"But we have found an option we believe will serve us well while Alviro is on international duty."
Somerset begin a Championship match against Middlesex at Taunton today – and captain Marcus Trescothick is eager for his team to transfer their YB40 form to the four-day arena.
Somerset have drawn three and lost the other of their four Championship games so far – and were fortunate to hang on for a draw at Yorkshire in their last outing.
But their 40-over form has been scintillating, with Trescothick's men following up their eight-wicket win over Unicorns with a 131-run drubbing of Yorkshire at Headingley.
"There's no real time to sit back and rest on what's been going on; we've got to make sure we get up for our four-day cricket, because we've been a little bit off par," said Trescothick.
"We need a victory as soon as we can. I think the win at the weekend shows that we're still there or thereabouts and that, as a team, we're very strong still.
"Internally, in our own minds, we know that we're good enough to win games, so it's a case of getting it together at the right time and making sure we get it right in a four-day game to get the victory we need.
"I'd like to transfer our 40-over form over to our four-day cricket – and get some better performances in that from a few more people."
Nick Compton is on international duty, so Somerset add all-rounders Craig Meschede and Lewis Gregory, plus bowler Adam Dibble to the side that drew with Yorkshire last week.
Somerset (from): M Trescothick (capt), A Petersen, A Suppiah, J Hildreth, J Buttler, P Trego, A Thomas, S Kirby, J Overton, J Leach, C Meschede, L Gregory, A Dibble.
