The short period of time between some Super League games is causing problems, says Warrington head coach Tony Smith.
Wolves had nine players out injured or suspended as they lost at Huddersfield on Sunday, and have just five days to prepare for Friday's trip to Hull KR.
Smith had just 18 fit first-team players to choose from for his matchday squad of 17 against the Giants.
"You don't have to be a genius to work out why - the short turnarounds are killers," he told BBC Radio Merseyside.
"All of us have got small squads in numbers so we're all getting tested at different stages.
"It's a bit of a game of attrition at the moment. It will be a testing week but that's what Super League is about."
Warrington have lost three of their last five games in Super League and sit sixth in the table.