The Philadelphia Eagles brought in five new players during Tuesday's opening of free agency, including three potential starters to a revamped defense in safety Patrick Chung, cornerback Bradley Fletcher and nose tackle Isaac Sopoaga.

The Eagles also added former Houston fullback/tight end James Casey and linebacker Jason Phillips in an active first day.

Chung comes to Philadelphia after a four-year tenure with the New England Patriots in which he often battled injuries, having missed 12 games over the past two seasons. A second-round pick in the 2009 draft, the 25-year-old's best campaign came in 2010, when he amassed 96 tackles, three interceptions and nine passes defensed.

The Oregon product is also familiar with new Eagles head coach Chip Kelly, who was the Ducks' offensive coordinator during Chung's final two college seasons.

Fletcher played his first four NFL seasons with St. Louis and started 15 games for the Rams in 2010, registering 75 tackles, four interceptions and 11 passes defensed. He served as that team's primarily nickel back last year and came up with 28 stops, one interception and one sack.

Both Chung and Fletcher should have an opportunity to start in an overhauled Philadelphia secondary that allowed a league-high 33 touchdown passes in 2012 and parted ways with high-priced cornerback Nnamdi Asomugha earlier on Tuesday.

Sopoaga, who made 71 starts for San Francisco over the past five seasons, will likely be the regular nose tackle in Philadelphia's new 3-4 scheme. The 330- pound run stuffer had spent his entire nine-year career with the 49ers and produced 27 tackles and one sack for the NFC champions last season.

The versatile Casey posted career highs of 34 catches, 330 receiving yards and three touchdowns for the AFC South champion Texans last season, and has compiled 66 receptions totaling 752 yards over his four years in the NFL.

Phillips had 22 tackles and made two starts for Carolina this past season. The 27-year-old broke into the league as a fifth-round draft choice of Baltimore in 2010.