The San Francisco Giants have demoted reliever Ryan Walker to Triple-A Sacramento following a disappointing stretch where he allowed seven runs in just 31⁄3 innings over his last four outings. Walker, who began the season as the team's primary closer after leading with 17 saves last season, struggled significantly, culminating in a poor performance against the Pittsburgh Pirates where he allowed two runs and retired only two batters. Manager Tony Vitello expressed hope that a minor league stint would help Walker regain his confidence, noting that the pitching coaches identified some physical issues affecting his performance. In addition to Walker, right-hander Gregory Santos was also optioned to Sacramento, while lefty Sam Hentges, who had a 1.93 ERA in the minors, was activated from his rehabilitation assignment. Righty Dylan Smith, with a 2.13 ERA in Triple-A, has been called up as the Giants attempt to address their bullpen issues. Currently, the Giants hold a disappointing record of 15-24, tied for the worst in the National League.