Stoke City manager Mark Robins said their EFL Cup exit at the hands of Bradford City showed they were "desperately light" in some areas.
The Championship leaders' lack of depth was exposed after they were beaten 3-0 by League One Bradford on Tuesday.
A heavily-rotated Stoke line-up went down 3-0 to the Bantams at the bet365 Stadium.
"It opens our eyes about where we are at. We've done some great business but we know where we are at," Robins told BBC Radio Stoke.
"We're desperately light in certain positions.
"That's not off the back of one result, that result is one we have to park, but we know we are desperately short of bodies in certain areas.