Khawaja has been called up to an Australia A training camp in advance of their tour of India later this month. Burns, meanwhile, will be returning to Australia to nurse a back injury.

[caption id=”attachment_77020″ align=”alignnone” width=”800″] Khawaja in action for Glamorgan against Surrey[/caption]

Burns himself was recruited as an injury replacement, stepping in for Shaun Marsh who was ruled out for the rest of the season with a shoulder injury.

Glamorgan chief executive Hugh Morris said: “It’s disappointing Usman and Joe will have to finish their stints at Glamorgan early.

[caption id=”attachment_77023″ align=”alignnone” width=”800″] Burns played just twice for Glamorgan before injury ended his season[/caption]

“Both players have been fantastic for the dressing room and Usman in particular has shown himself to be a world-class batsman with his performances.”

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The double blow leaves Glamorgan without an overseas player at a crucial stage of their T20 Blast campaign. They could yet announce a replacement. Glamorgan are one point of fourth place in the South Group after a thrilling win at The Oval on Tuesday night, chasing down Surrey’s 194 with an over remaining.