Foster will be without Mils Muliaina, Sitiveni Sivivatu and Byron Kelleher for the opening seven rounds of the competition as they are in the All Blacks' World Cup conditioning squad.
But New Zealand's World Cup preparations have hit other franchises harder, leaving holders Crusaders without nine players to start with.
The Hamilton-based franchise has long under-performed in the tournament, but could become leading contenders on the back of the form shown by their Waikato players in domestic competition.
However, goalkicker David Hill's move to Bristol has left the team without four of Waikato's national championship-winning side.
"That's our challenge, because our forwards are pretty much intact from round one to 13 but our backs are going to require a lot of work," Foster told The Waikato Times.
Jono Gibbes, Brendon Leonard and Sione Lauaki have minor injury problems but the majority of the squad is on track to be ready to take on the ACT Brumbies at Waikato Stadium on February 3.