PHILADELPHIA -- The Phillies made some decisions Friday to protect four players from next month's Rule 5 Draft.

They placed right-hander Phillippe Aumont, left-hander Jacob Diekman, catcher Sebastian Valle and outfielder Tyson Gillies on the 40-man roster.

Aumont and Gillies joined the organization in December 2009 in the trade that sent Cliff Lee to the Seattle Mariners. Aumont, 22, went 2-5 with seven saves and a 2.68 ERA in 43 appearances for Double-A Reading and Triple-A Lehigh Valley in 2011. He struck out 78 batters in 53 2/3 innings and held opponents to a .216 batting average. The Phils envision Aumont as a late-inning reliever in the future, possibly a closer. MLB.com ranks Aumont as the organization's 10th-best prospect.

Gillies, 23, has been unable to stay on the field since joining the Phillies because of injuries. He played in just three games for Class A Clearwater in 2011, but played for Scottsdale in the Arizona Fall League.

Valle, 21, hit .284 with five homers and 40 RBIs in 91 games for Clearwater. He hit .368 against left-handed pitching. The Phils signed Valle as an amateur free agent in 2006. MLB.com ranks Valle as the organization's second-best prospect.

Diekman, 24, went 0-1 with a 3.05 ERA and three saves in 53 appearances with Reading this past season. He allowed 13 earned runs in 18 innings in his first 18 appearances, but had a 1.72 ERA over his final 35 appearances. He also struck out 83 batters in 65 innings and held opponents to a .199 average, including a .099 mark against left-handers. Diekman, who the Phillies selected in the 30th round of 2007 First-Year Player Draft, allowed one earned run and struck out 14 in 11 1/3 innings in the Arizona Fall League.

Two players not on the 40-man are right-hander B.J. Rosenberg, who pitched for Scottsdale in the AFL, and outfielder Jiwan James, who MLB.com ranks as the organization's No. 8 prospect. Both are eligible to be selected in the Rule 5 Draft.