BALTIMORE -- Colin Kaepernick got planted on his back on his very first pass of the 49ers' exhibition season.
That's not an optimal start, even if Kaepernick escaped injury and was excused after that game-opening, field-goal drive in Thursday night's 23-3 loss to the Baltimore Ravens.
The 49ers' makeshift offensive line is now a pressing concern, especially as right guard Alex Boone continues his contract holdout. The line had noticeable hiccups on its debut series with three newcomers: center Daniel Kilgore, right guard Joe Looney and right tackle Jonathan Martin.
"We have some work to do," coach Jim Harbaugh said of his team's overall play, citing specific concern for how the defense "got pushed around" while the offense needs to sustain drives better.
Defensively, the 49ers deployed a barrage of backups and sat most would-be starters, including outside linebacker Aldon Smith, who met earlier Thursday with NFL commissioner Roger Goodell regarding possible punishment for off-field conduct.
Young prospects highlighted the 49ers' night. Rookie Carlos Hyde debuted nicely (five carries, 39 yards), and superb plays came from second-year defensive linemen Quinton Dial (10 tackles, two forced fumbles) and Tank Carradine (eight tackles, one sack).
All that could have been inconsequential if Kaepernick had been hurt on his first pass attempt.
After eluding left guard Mike Iupati, outside linebacker Pernell McPhee launched his 280-pound frame into Kaepernick, who had just unleashed an incomplete pass to Stevie Johnson. That earned McPhee a roughing-the-passer penalty.
"It wasn't necessarily that I saw him, but I felt him," Kaepernick said. "You kind of know when you have a 300-pound man right next to you."
Kaepernick bounced right up and showed no ill effects, a reminder of the durability that's helped him make every start since replacing Alex Smith midway through the 2012 season.
Harbaugh said of the play: "I looked back and saw that he was down, so I didn't see the shot. I didn't think he was hurt."
Kaepernick downplayed the situation, figuring the 49ers benefitted from the penalty and ultimately reached the red zone with a shot at a touchdown.
That drive, however, yielded only a Phil Dawson field goal after another offensive-line miscue. Looney couldn't stop nose tackle Brandon Williams from reaching Jewel Hampton for a 1-yard loss on third-and-1 at the Ravens' 6-yard line. "As the preseason goes on, we'll get better," Looney vowed.
The shaky line play might prompt the 49ers to expedite an end to Boone's holdout, which has carried over from all offseason into training camp. Boone started every game the past two seasons at right guard.
Harbaugh and Kaepernick both thought the line had a positive first series, and running room indeed was created for Hyde, a second-round draft pick who started in place of Frank Gore.
"It felt great, and I missed so much being out there just playing football," said Hyde, a former Ohio State star.
Count Kaepernick impressed: "Carlos Hyde looked really good. He ran explosively, made good decisions, had the speed to hit the edge and creased some things inside."
Hyde's carries on the first series went for 7, 19 and 8 yards. His second series was highlighted by his block of a blitzing defender, allowing Blaine Gabbert to convert a third-down pass.
Said Gabbert: "We didn't execute the way we know we can. That caused us to be in some third-and-longs and some other unfavorable situations, and we turned the ball over too much."
Rounding out that starting lineup were cornerbacks Chris Culliver and Perrish Cox, inside linebackers Chris Borland and Michael Wilhoite, outside linebacker Dan Skuta, nose tackle Mike Purcell, safety Antoine Bethea and defensive tackles Demarcus Dobbs and Tony-Jerod Eddie.
Denver at 49ers, 1 p.m. Ch. 5
Aldon Smith meets with Goodell. PAGE 6