Saints inflicted a home defeat on Warrington for the first time in 2016.
“We had way too many errors, especially early in the tackle count,” Gidley told Sky.
“They played well, we made it really hard for ourselves though. Probably 25 points is unacceptable in where we want to be.
“I just thought we were a little bit off defensively tonight. It was frustrating.”
Sandow is some weeks away from a return to action.
“For me and Stefan its about getting our combinations working throughout training,” Gidley said.
“Obviously me and Chrissy have been working together since I arrived in November, its been really enjoyable. It’s now time for me and Stef to work on that.”