Cook, who plays JJ, was controversially dropped from the show last summer.
However, TV Line claims that she will reappear in an episode of the show scheduled to air in the spring.
Cook is reportedly due to start filming her scenes this week, but details of her storylines have not yet been revealed.
Criminal Minds airs on Wednesdays at 9/8c on CBS.
> Vangsness 'misses female Minds co-stars'