The Cumbrians have won just one of their last eight games but Abbott believes their season will turn when he has a fully-fit squad.
Saturday's defeat by Sheffield United came without James Berrett, Peter Murphy, Frank Simek and Lee Miller.
"We have no choice, the players have no choice, I have no choice. As a group, manager and a team we've got to be miles better defensively, simple as that," he told the News & Star.
"There's no magic formula. We have to defend better, stop goals going in, and have to work even harder.
"We've tried everything. We've got another three or four who are going to be coming back, then we've got options, and can look at how we do things - but it's no consolation to anybody at the minute."
- Sports & Recreation
- James Berrett
- Frank Simek
- Sheffield United