PHILADELPHIA (973espn.com) - Isaac Seumalo's ascension to the starting left guard spot takes a bit of a detour this weekend as the rookie will miss Saturday’s dress-rehearsal preseason game against Andrew Luck and the Indianapolis Colts.

The third-round pick, who ascended to the starting position once Allen Barbre was moved to right tackle after it became clear that Lane Johnson would be suspended for 10 games, will miss the contest with a strained pectoral muscle, according to Eagles head coach Doug Pederson.

"He has a strained pec muscle that is day-to-day," Pederson said of Seumalo. "We feel [it’s] best for his interest to keep him out of this football game."

Veteran Stefen Wisniewski, who has been working as the backup right guard and center, will get the start in Seumalo’s place. Pederson, however, said Seumalo would not be losing his starter status because of the injury.

"I'm not saying (Wisniewski) can't win it (the starting LG job), but I'm saying right now I'm not going to let an injury keep Isaac out of the starting rotation," Pederson said.

Joining Seumalo on the sidelines will be wide receiver Jordan Matthews (knee), defensive tackle Mike Martin (knee), rookie defensive end Alex McCalister (calf) and receiver Hunter Sharp (hamstring).

Matthews had originally hoped to be back this week from the bone bruise suffered in his knee during practice earlier this month when rookie corner Jalen Mills tackled him low in a live period.

Speaking earlier this week, Matthews said he expects to be back by Week 1 of the regular season.

Martin, meanwhile, just returned to practice from his own knee injury but the Eagles are erring on the side of caution with him. Despite not playing in the preseason to this point Martin is expected to be one of the backups at defensive tackle behind Fletcher Cox and Bennie Logan.

"He's a veteran guy that understands how to play [and] how to get himself ready to play," Pederson said of Martin. "He's also in a position where you're probably not going to lean on him for more than 15, 20, 25 snaps a game. And that's what you want out of him. Just getting him to the gate on Sundays is obviously where you want to be and what you want to do."

Sharp, an undrafted rookie out of Utah State, was waived on Wednesday afternoon after the team reached an injury settlement with him.

Also out against the Colts as expected are Carson Wentz, who is still dealing with his fractured rib, cornerback Aaron Grymes, who is shelved for the rest of the preseason with an AC joint injury in his shoulder, and rookie linebacker Joe Walker, who will eventually head to IR with his torn ACL.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen