BETHLEHEM, Pa. - The competition for the Eagles' backup quarterback job became even more intriguing on Saturday when it was revealed that Mike Kafka has a fractured left hand and will be limited for about three weeks.

The injury is to his nonthrowing hand, so Kafka will be able to participate in some drills but will not be able to take snaps.

The development was announced two days after the Eagles' 24-23 win over the Steelers in Thursday's preseason opener, during which rookie Nick Foles appeared to outperform Kafka. Foles finished 6 for 10 with 144 yards and two touchdowns in the third quarter against the Steelers. Kafka went 5 for 9 for 31 yards with an interception.

Kafka's hand was stepped on during his first series, but he played through the injury and did not know the extent until after the game.

He was still on the field on Saturday participating in 7-on-7 drills and in individual work, but not in team drills.

"I'm practicing," Kafka said about when he'll return. "I'm going to keep on working, get better every day. And Coach [Andy] Reid makes those decisions."

While he is sidelined, though, Foles will receive an opportunity to continue to impress the coaches. Foles has the stronger arm of the two. He is still learning the system, but the Eagles are confident in the third-round draft pick.

Now, they get to see him with the second unit.

"I feel really comfortable," Foles told reporters. "In different drills and different things, there is a mixture of different players. I've been with different O-linemen.

"Whether it's in the cafeteria, in the dorms, or in the meeting rooms, just getting to know the guys [is important] because when you're in the huddle, they already know you and you're all familiar. I feel really comfortable with all the guys."

Vick practices

While the Eagles are monitoring Kafka's left hand, they do not need to be concerned about starting quarterback Michael Vick's left hand. Vick injured his thumb on Thursday when he struck center Jason Kelce's helmet on a follow-through.

After an initial scare, the injury was diagnosed as a contusion that feels like a stinger on the thumb. Vick was playing with yellow Play-Doh after Saturday morning's walk-through to strengthen the muscles and continue eliminating swelling.

Vick termed it a minor "freak injury" that he has dealt with before. Vick said he suffered the same issue in the 2011 season finale against Washington and played through it. He finished with 335 yards passing and three touchdowns that day.

"I know how to deal with it," Vick said.

Maclin, others sit

Wide receiver Jeremy Maclin, running back Dion Lewis, and defensive tackle Cullen Jenkins missed practice with "slight" hamstring strains suffered on Thursday. Offensive lineman Brandon Washington remains out with a concussion, while defensive end Jason Babin (calf), wide receiver Riley Cooper (collarbone), linebacker Jamar Chaney (hamstring), and cornerback Cliff Harris (ankle) were also out.

Linebacker Casey Matthews was an unexpected absence from practice because of an ankle injury, and cornerback Curtis Marsh left early with a hamstring injury.

None of the injuries seemed to be major concerns. Maclin said he aggravated his hamstring while accelerating during Thursday's warm-up but hopes to be ready for Sunday's practice.