Croft will miss the remaining matches of Glamorgan's season to correct the niggling complaint, which was diagnosed as a tiny cartilage tear.
Although the short-term prognosis was good, the club's medical advisers consulted the England management and felt it was sensible to correct the defect now as the team depart for Australia within six weeks.
Somerset are hoping to sign Paul Jarvis, the former England and Yorkshire fast bowler. The 33-year-old was released by Sussex last month and visited Taunton for talks with Somerset officials over the weekend.
Jon Dakin, who took a hat-trick in Leicestershire's AXA League win over Middlesex on Sunday, is to sign a new contract with the club.
The Western Australian Cricket Association have cancelled next month's inaugural World Super 8s tournament due to top players having other international commitments.
This applied to Australia, who would have fielded a second string with the Test squad touring Pakistan.
One second string who had something to celebrate yesterday were Northamptonshire. While the first XI may be enduring a torrid season, the club's second team won the AON Trophy for the second time as they overcame Derbyshire with some ease.
Should they defeat the same opposition in the three-day game starting tomorrow at Derby, they would win the Second XI Championship for the first time since 1960 and complete a notable double.
Only some typically lusty blows from Phillip DeFreitas, who clubbed four sixes in his half-century, ensured an adequate total from Derbyshire.
In response, the England Under-19 player Graeme Swann played well before losing his off stump and it was then left to his elder brother Alec, with an unbeaten 57, to guide Northamptonshire home with 12 balls to spare.
At Hove, Warwickshire overpowered Sussex by 85 runs in the inaugural ECB County Board Knock-Out final. The match, scheduled for two days, was reduced to a one-day, 60 overs-a-side contest after the original venue at Horsham was hit by rain.
James Troughton, from Stratford-upon-Avon, struck 73, the highest score of the match, as Warwickshire scored an impressive 254 for nine. Sussex were never in the hunt and were dismissed for for 169 in 54 overs.
2ND XI AON TROPHY FINAL.- Northampton: Derbys 199 (50 overs; P A J DeFreitas 58); Northants 203-5 (48 overs; A J Swann 57 not). Northants won by 5 wkts.
ECB COUNTY BOARD KO FINAL (Hove): Warwicks 254-9 (69 overs, J Troughton 73); Sussex 169 (54 overs, K Bray 3-19, A Farooque 3-27). Warwicks won by 85 runs.