Doncaster won their opening match of the campaign, beating Workington Town 22-12 despite trailing 12-0 inside the first 10 minutes.
But Cooke said: “A performance as gritty as that is no good if we put a poor one in at the Keepmoat this weekend.”
Doncaster are without long-term injury absentees Brett Waller and Lee Waterman, while Ash Lindsay and Lewis Graham could both return to action for Keighley Cougars, who started their season with a 36-14 triumph over Whitehaven.
Keighley coach Paul March said: “We took our opportunities when they came along and hopefully we can do the same again this week, but we can’t get carried away.
“The big teams always take their opportunities and we need to be doing that if we want to compete. On paper our squad is good enough to compete at this level, and we’re definitely looking to get into the second tier of 12 in 2015.”
On Doncaster, March added: “It’s all about what we do; as long as we’ve got our own house in order we shouldn’t be worrying about anything else, but we know Paul Cooke is a major part of what they do.”