Worcestershire are resigned to losing spinner Saeed Ajmal for the rest of the season once he leaves for international duty with Pakistan later this month.
Ajmal will play in three more T20 Blast games and the County Championship game with Leicestershire, starting on 13 July, before joining up with Pakistan.
Worcestershire had hoped Ajmal might return once his country's mini-series with Sri Lanka is over on 30 August.
Director of cricket Steve Rhodes said: "It is doubtful he would come back."
He added to BBC Hereford & Worcester: "It will be very difficult. The guy has been on the go non-stop for a hell of a period of time and Pakistan have got important cricket coming up.
|Number one Saeed|
|Saeed Ajmal recorded his sixth five-wicket haul of the season in the win over Glamorgan.|
|The Pakistan spinner, the country's leading wicket taker, has taken 56 wickets in eight Championship matches this summer.|
|That includes two 10-wicket match hauls, his 12-40 against Glamorgan having been bettered by his 13-94 against Essex, the best match figures by a Worcestershire bowler at New Road since war broke out in 1939.|
|Worcestershire are now unbeaten in their last 12 Championship games, their longest unbeaten run since 2002-03.|
"I know their board wanted him to have a bit of a breather. But the way things work out it would only be for two Championship matches.
"What I would say is I'm hopeful we can try our best to secure Saeed to come back for periods next season. I know he enjoys his time here but we shouldn't take that for granted."
Ajmal is the Championship's leading wicket taker, with 56 victims in eight matches this summer at 15.91, to inspire four of his side's five victories.
The wily 36-year-old Punjabi has also claimed eight scalps in Twenty20 cricket, at a miserly economy rate of just six an over, to help his team top the North Group in the T20 Blast, as well as Division Two in the Championship.
But Rhodes admits that, although Ajmal will leave a big hole, the arrival of 28-year-old New Zealand international left-arm paceman Mitchell McClenaghan as his replacement will help plug the gap.
|Pakistan in Sri Lanka|
|Wed 6 - Sun 10 August - first Test, Galle|
|Thu 14 - Mon 18 August - second Test, Colombo (PSS)|
|Sat 23 August - first one-day international, Hambantota|
|Wed 27 August - second one-day international, Colombo (RPS)|
|Sat 30 August - third one-day international, Dambulla|
"It is going to be a struggle," added Rhodes. "But we are very lucky with Mitchell McClenaghan coming in."
Worcestershire's hopes of guaranteeing a top two place in the North Group to ensure their first-ever Twenty20 home quarter-final rest largely on how they perform in this weekend's two home games against Yorkshire and Lancashire.
In what will be his last two T20 appearances at New Road, Ajmal is likely to prove a big factor, but Worcestershire will again be without new England Test all-rounder Moeen Ali.
"Both games will be really tough," said Rhodes. "Yorkshire are going well. And Lancashire are a team you must respect, with some terrific players.
"It is quite tough for us when we haven't gone Moeen playing for us. But we will just try and approach the game like we have with every single game, to make sure we are doing our job right.
"Hopefully if we can do that, then it should be good enough to take care of the opposition."