Australian batsman Justin Langer has signed a short-term deal with Somerset, subject to cricket board approval.
Langer is also in talks to spend the 2007 season at Taunton
Langer, 35, is expected to arrive at the end of June, while countryman Dan Cullen, is on duty with Australia A.
"Justin offers tremendous help both on and off the pitch and will be a great asset during the six weeks he will be with us," said Somerset's Brian Rose.
"He will also be an informal coach because he has got a great rapport with the younger players."
Langer has played 100 Tests, hitting 7,393 runs at an average of 45.35.
He played three seasons for Middlesex between 1998-2000, scoring 3,968 first-class runs at an average of 61 and captaining the side in his last year.
He turned down an offer from Derbyshire for this season but, after suffering rib and hamstring injuries during the winter, decided he wanted to play more regularly.
Director of cricket Rose also revealed he is in talks with the left-hander over a longer deal for next season.
"He feels it is unlikely that he is going to get chosen for the World Cup and he wants to further his career in first-class cricket," Rose told the Somerset website.
"If he does come back to join us in 2007 we would be delighted because we have a young side."