Another week of preseason football, another week the Philadelphia Eagles have lost a backup quarterback due to injury. 

On the Eagles' first offensive series in Thursday's preseason win over the Jaguars, Cody Kessler was knocked out of the game with a concussion. The Eagles are not playing Carson Wentz in two preseason games, so they were left with fifth-round rookie Clayton Thorson to finish the game.

Thorson entered training camp battling for the No. 3 quarterback spot, but is the backup quarterback to Wentz until Kessler returns. Philadelphia, also without No. 2 quarterback Nate Sudfeld for six-to-eight weeks with a broken wrist, is thin at quarterback. 

Head coach Doug Pederson will hold off on the Eagles actually signing a quarterback until the team gets more information on how long Kessler will be out.

"You know what, we'll evaluate Cody again tomorrow and over the weekend, but we're going to get through the next few days, we're going to evaluate everything," Pederson said to reporters after the game. "Obviously really excited for Clayton (Thorson) tonight, obviously getting a lot of time. You know, we're just going to evaluate where we are and make a decision as we go." 

The Eagles could play Wentz the third preseason game against the Baltimore Ravens, but they could need a third quarterback if they decide to rest him and go with Thorson as the starter. Philadelphia's emergency quarterbacks are Greg Ward and Braxton Miller, both who played quarterback at the University of Houston and Ohio State University, respectively. 

The Eagles do have an option at quarterback who knows the system in former Alliance of American Football quarterback Luis Perez, who was with the Eagles earlier this offseason before the team signed Kessler to a contract. 

Kessler has played fewer than two quarters this preseason, raising questions if that's enough playing time to be the No. 2 quarterback until Sudfeld returns at the end of September. Until the results come in on the severity of his concussion, Pederson will hold pause. 

"It's still early," Pederson said. "Obviously this is what the preseason is for, to give these guys an opportunity. We still got a couple preseason games left and we're going to do our due diligence to make sure we see enough from everybody to make educated decisions at the end."