Jayden Daniels took his first game reps in 256 days, and Terry McLaurin lined up opposite Stefon Diggs for the first time. But the focus of the Washington Commanders’ second preseason game — a 17-13 loss to the Lions in Detroit on Saturday — was their supporting cast, a group that could determine the outcome of this season.That group includes an offensive line that is currently without two key starters because of injuries. It includes a receiving corps with a handful of players fighting for what could be one of the last spots on Washington’s initial 53-man roster. It includes defensive reserves whose biggest impact may ultimately be felt on special teams. And it could even include the third-string quarterback.Here are some of the biggest takeaways from Saturday’s loss and what was said thereafter:Top Plays from Commanders @ LionsThe offensive line is an issueWashington needs more help on the O-line. Maybe you’ve heard me say that before. Sure, Daniels and the (healthy) starters played all of three snaps and spent only a minute and a half on the field together. Coach Dan Quinn said it was always the plan to give Daniels one drive, no matter how long that drive lasted. But that series — a three-and-out — showed plenty of what the Commanders are missing.Daniels was quickly pressured into an incompletion on his first snap when linebacker Devin White pushed back center Julian Good-Jones. Then Daniels was sacked for a loss of 10 yards after edge rusher D.J. Wonnum beat tight end John Bates on the inside.Daniels handed it off to rookie back Kaytron Allen for an 11-yard gain on third-and-20.Good-Jones has been the primary fill-in at center for Nick Allegretti, who has been dealing with a calf injury for most of training camp, and his lack of experience has often showed, leaving Daniels under duress as the interior of the line gets pushed back. It has also raised the question of whether Washington has enough reinforcements inside; rookie Matt Gulbin impressed in the preseason opener against Miami, but did not play at all with Daniels on Saturday.When asked about the offensive line after the loss, Quinn praised the play of right guard Sam Cosmi — he’s “maybe playing the best that I’ve seen him play,” Quinn said — and the coach has also been pleased with the play at left tackle in the wake of Laremy Tunsil’s serious triceps injury. But “we got work to do to figure out where we want to get to at center,” Quinn noted.The defense makes a markThe Commanders’ defense starred in this game, immediately making up for its disappointing opening drive in the first preseason game, when it gave up 93 yards and a touchdown to the Dolphins.