Manawatu, with only one win, is the next opponent tomorrow night, also at Rotorua International Stadium.
"Playing those premiership teams does take it out of you," says Gibbs. The Steamers have played Taranaki, Counties-Manukau, Canterbury and North Harbour from the top division.
"That's not an excuse. There's not one thing that you can put your finger on. The boys are trying really hard and we've been training really well, but it just hasn't been transferred into the game," he says.
"We're still hugely confident we're going to make the semifinals. We know we pretty much need to win the rest of the games. If we do that, and depending on what the other teams do, there's probably potential there for a home semi."
There are a couple more injury concerns though. Experienced and accomplished second-five Terrence Hepetema is doubtful, while flanker Hugh Blake's latest shoulder problem may mean the end of his season.
Mitch Karpik, who was on the bench against Waikato, is likely to return to the starting line-up which may not be confirmed until close to match time.
Crucially Liam Polwart, the man who started the season as captain and first-choice hooker, remains a week-to-week proposition because of a nerve injury in his neck.
In a forward pack that has often struggled, Gibbs knows his absence has been huge.
"From a scrummaging perspective, and lineout throwing and leadership, he has left a big hole. But in this competition, because of the shortness of it, if you pick up a couple of key injuries in key areas, then it can really hurt."
The Steamers have been missing not just Polwart, but also talisman first-five Mike Delany who's out for the season, while veteran flanker Tanerau Latimer also has to be assessed weekly.
That gives other players a chance to impress but it's close to desperation time in the Steamers' campaign. They cannot afford to lose to Manawatu.