DETROIT — Blake Bortles insists he's content to be a backup.
He might be starting soon enough if he keeps playing like this.
Bortles threw for 158 yards and a touchdown for Jacksonville on Friday night, and although the Jaguars lost 13-12 to the Detroit Lions, their rookie quarterback was a bright spot in an otherwise sloppy game.
"Blake, he made a couple of mental errors in checks. But there was one where he checked us into something that we weren't anticipating and he made a big play off of it," coach Gus Bradley said. "I like that he takes risks. I like that he's aggressive. He'll attack the situation when he's in it and it's not too big for him. So all those things are really good signs."
Bradley said Chad Henne is still the team's starter. Henne went 9 of 14 for 70 yards.
"This has been a perfect situation for me, because it has been a stress-free learning experience," Bortles said. "I knew on Day One that Chad was going to be the starter, and I've been able to just focus on learning from him. When he's on the field, I'm his biggest fan, because I want to see things going right and learn how it works in the NFL."
Bortles completed 10 of 16 passes, including a 13-yard touchdown to Allen Hurns.
The teams combined for 27 penalties.
Jaguars defensive tackle David Carter left in the fourth quarter with a sprained MCL, and defensive tackle Sen'Derrick Marks is expected to have an MRI on a shoulder injury. Free safety Winston Guy Jr. hurt his left ankle, but tests came back negative.
Detroit's Reggie Bush broke free for an 86-yard touchdown run in the first quarter. Calvin Johnson played for the first time this preseason, catching two passes for 27 yards, but Matthew Stafford was intercepted once and the Lions struggled in the red zone.
Detroit was stopped on fourth down inside the Jacksonville 5-yard line in the first half, and Mikel Leshoure lost a fumble deep in Jaguars territory in the fourth quarter. Ryan Broyles had a fumble at the Jacksonville 1 overturned on replay.
George Winn scored from there to give Detroit a 13-12 lead with 7:12 remaining.
Even when Detroit's top players were in, the Lions struggled at times. Stafford nearly had two passes intercepted on the first drive, and after Bush scored on his long run later in the quarter, Stafford was intercepted by defensive end Andre Branch on the first play of Detroit's third possession.
"That kid needs to play some tight end," Stafford said. "It was a good play by him. I obviously would love to have that one back."
Jacksonville's Josh Scobee kicked a 38-yard first-quarter field goal but was replaced by Kasey Redfern because of a quadriceps injury. Redfern made a 34-yarder in the second quarter but had a 45-yard attempt blocked in the third.
Henne avoided any major mistakes, but Bortles, the first quarterback taken in this year's draft, was able to move the Jaguars down the field. Jacksonville started at its own 5 with 1:43 remaining in the first half, and Bortles guided the Jaguars into position for Redfern's kick as time expired.
In the third quarter, Bortles took the Jaguars from their own 14 to the Detroit 27 before Redfern's kick was blocked by Xavier Proctor. On its next drive, Jacksonville went 49 yards in four plays for its only touchdown.
Hurns had seven catches for 113 yards.
Jacksonville's Denard Robinson, a star quarterback when he was at Michigan in nearby Ann Arbor, got a nice cheer from the crowd in the first quarter when he made a tackle on special teams.
NOTES: Detroit FB Montell Owens was evaluated for a possible first-quarter head injury, and coach Jim Caldwell said he didn't have an update afterward. Lions LB Kyle Van Noy sat out with an abdominal injury. ... Bradley said Scobee's injury wasn't too serious. ... Robinson tried to tweak rival Michigan State, even after the Spartans won the Rose Bowl last season. "It did sting a little, but at least it was a Big Ten team," Robinson said. "And it was good that our little brothers won the Rose Bowl."