Twins pitcher P.J. Walters has passed through release waivers without being claimed by another major-league team, according to the website MLBTradeRumors.com. That greatly increases the likelihood that Walters, who was designated for assignment last Thursday, remains in the Twins' organization at Class AAA Rochester.

As a player whose contract has been outrighted before, Walters has the option to become a free agent or accept the Twins' assignment to Rochester, where he could be recalled later in the season if placed on the 40-man roster once again. It was Ron Gardenhire's hope, he made clear last week, that Walters would stay in the organization.

Walters won his first two starts with the Twins in May, but went winless in his last six and posted a 5.95 ERA overall. The righthander lost his spot in the rotation last week when the Twins activated Mike Pelfrey from the disabled list.

Walters, who has also pitched for the Cardinals and Blue Jays, was 4-2 with a 3.31 ERA at Rochester before being called up in May.