The former Derby County, DC United, and Plymouth boss resigned after leaving the team bottom of the Championship.
The 39-year-old was given resources and a chance to be a success, but was not able to deliver.
"Raising our profile was not one of the considerations in hiring Wayne Rooney," he wrote in an update shared on the club's official website.
"We thought that he would be able to help us win football matches. During Wayne’s tenure as Head Coach, we saw glimpses of what was possible, but clearly both results and underlying performances were showing few signs of being at the level we need.
"We thank Wayne for what he did achieve in his months at the Club. He united the players, helped restore a positive attitude at the Club and won over the fans whose support had been tested for a few months in 2024. His approachable nature and down to earth personality made him a popular figure and we will miss him."