In late 2373, Starfleet sent orders to Ramirez to gain information on a new Dominion battleship, that was believed to be near the Valiant's position.
The Valiant was in the Kepla sector when the Dominion War began. Consequently, Ramirez ordered the Valiant back to Federation space. On their way home, the Valiant encountered a Cardassian battle cruiser near El-Gatark. The two ships began to attack each other and both ships lost main power. Ramirez himself was injured with a puncturedlung, but managed to get the Valiant's systems back online and the Cardassian ship was destroyed.
In the third edition of the Star Trek Encyclopedia, an asterisk was used in the supplement section to identify entries which added information to entries in the main body of the encyclopedia. In the case of Captain Ramirez, this was not the case, suggesting that the authors believed that there were two Captain Ramirezes. On p. 399, the first Captain Ramirez is identified as a spaceshippilot and, on p. 652, the second Captain Ramirez is identified as a Starfleet officer.