The 30-year-old Kiwi, who stood in for Ferguson earlier on in the season, will arrive in England on Thursday to replace the 34-year-old Australian as the county's overseas signing
Worcestershire have brought Hamish Rutherford back into their squad for the remainder of the season in place of Callum Ferguson, who is flying back to Australia for personal reasons.
Rutherford, who stood in for the 34-year-old Australian in the first month of the domestic season, has now returned for this season's final three County Championship matches and Worcestershire's bid to retain their T20 Blast crown.
The 30-year-old Kiwi, who therefore replaces Ferguson as the county's overseas signing, made a century in his only Championship appearance this season, which came in the Pears' win over Leicestershire in April.
Worcestershire chairman Paul Pridgeon told the club's official website: "Hamish is returning for the final part of the season and is looking forward to coming back.
"He made a great impression with the bat and forged a nice bond with the boys.
"Callum is leaving here early for personal reasons which we fully respect."
Rutherford is due to fly into England on Thursday and may be considered for selection for Friday's Blast derby against Birmingham Bears at Edgbaston.
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