Phillips says in a statement released by ESPN Wednesday that he's sorry to have "put his family and colleagues through this."
ESPN has granted Phillips' request for time off, and has taken unspecified disciplinary action.
Police say 22-year-old ESPN production assistant Brooke Hundley called Phillips' wife in August after he broke off the affair and sent her a letter graphically describing their relationship.
Phillips says he will not press charges. The status of the police investigation was unclear Wednesday.
ESPN says Hundley is still working for the network.