The Red Sox continued to make changes to their beleaguered pitching staff in anticipation of the September stretch yesterday by claiming right-handed reliever Chad Harville off waivers from the Houston Astros. Another significant move could be coming today with the addition of Steve Trachsel. Sources from multiple teams said the Sox and New York Mets were involved in serious discussions last night about a deal that would bring veteran right-hander Trachsel to Boston for one or two minor leaguers. Trachsel returned to the mound for the first time in five months (following surgery to repair a herniated disc in his back) Friday and allowed only two hits in eight scoreless innings against the San Francisco Giants, but he learned shortly thereafter that he was being skipped the next time through the Mets' rotation. Trachsel and New York GM Omar Minaya denied Sunday that a trade was being mulled, but that apparently changed yesterday. One source said that the Sox and Mets were close enough to a deal that they were simply settling on the minor leaguer(s), but another said that the sides weren't close but were still talking. Trachsel, 34, has cleared waivers, which facilitates a deal. Players need to be in an organization by the end of August to qualify for inclusion on postseason rosters.