Vaz Te dislocated his shoulder in West Ham's Premier League defeat against Arsenal at Upton Park two weeks ago and the Portuguese had keyhole surgery on Monday in a bid to cure the problem.
The former Bolton and Hibernian star has been a key member of West Ham's squad since signing from Barnsley in January and he fired the east London club into the Premier League last season when his late winner clinched a 2-1 victory over Blackpool in the Championship play-off final.
Allardyce told the club's website: "We think we've chosen the best option to strengthen the shoulder and get him back as quickly as we can."
While Vaz Te's absence will be a blow to West Ham, Allardyce is convinced his squad has enough strength in depth to cope with the 26-year-old's absence.
"We've got some good players ready to step up in place. Matt Taylor has been there and there are others in the squad that haven't quite played as much such as Gary O'Neil," Allardyce added.
"Whichever option we pick it's up to them to step up to the mark. They need to provide the attacking opportunities that we need."
