There was something eating at Vikings receiver Justin Jefferson after Sunday's 31-29 loss to the Lions.

It wasn't a relatively mediocre 81 receiving yards, ranking seventh in the otherwise dominant nine career games Jefferson has played against the Detroit Lions. He averages over 125 yards per game against the Lions, including Sunday's loss.

It wasn't Jefferson's sporadic role Sunday, when half of plays he was targeted on — four of eight —came on a single drive to open the second half.

It was a Vikings offense that couldn't get out of its own way: penalties, drops and missed throws.

The Vikings offense committed four presnap penalties, including two by receiver Jordan Addison, a false start pegged on center Garrett Bradbury and the late illegal formation when players hurriedly tried to line up for a spike to stop the clock. The Vikings entered Sunday averaging a league-worst three presnap penalties weekly.

"We knew coming into this game that it was going to be a battle, wasn't going to be an easy cakewalk," Jefferson said. "But we definitely hurt ourselves in plenty of ways that y'all probably can't see. But there on that field, we missed plenty of opportunities. We just have to be better, especially all the flags we had. We just have to be better all around."

What self-inflicted issues could we not see?

"Getting the two-point conversion toward the end of the game, that would've helped tremendously," Jefferson said. "Getting that third down toward the end of the game would've helped. Just plays being left out there on the field. But it's no single person's fault. We all have to be dialed in as a whole entire team."

Quarterback Sam Darnold appeared to make mistakes on both of the plays Jefferson mentioned. When the Vikings lined up for a two-point try after linebacker Ivan Pace Jr.'s fumble recovery for a touchdown in the fourth quarter, Darnold fired an incomplete pass into tight coverage toward Addison.

On the same side of the field, coach Kevin O'Connell said, Darnold "might have had Speedy," referring to receiver Jalen Nailor, in a one-on-one matchup on a fade route to the back pylon.

When the Vikings regained possession with four minutes left, they had a chance to drain the clock.

But on third-and-4, Darnold overthrew Jefferson near the sideline.

"Could have put it on him a little bit more, a little bit better," Darnold said.

Darnold completed 22 of 27 throws for 259 yards, a touchdown and an interception.

Those numbers don't tell the tale of how Darnold and the Vikings offense struggled to maintain and finish drives. Five times they crossed midfield into Lions territory, but only once did that drive end in a touchdown. That was at the top of the third quarter, when Darnold found Jefferson for a 25-yard score.

The Vikings also got three field goals and threw an interception on those marches into Lions territory.

Darnold's interception came when he apparently missed seeing Lions safety Brian Branch, who broke on a crossing route by Addison and made an impressive leaping pick.

"Sam made so many good decisions today," O'Connell said, "threw so many highly competitive throws to give our guys chances — touchdown to Justin included — and they got us on that [interception]."

Presnap woes will remain a focal point of the Vikings coaching staff. The offense ended up in situations such as third-and-17, second-and-14 and first-and-15 because of false starts or illegal formations.

"That's positions that a lot of people in this league cannot convert," Jefferson said. "We just got to be better before the play snaps."

The Vikings also burned an early timeout in the first quarter, seemingly to avoid a delay-of-game penalty caused by communication lapses between Darnold and O'Connell.

They've shown the talent for big plays, whether Addison's 51-yard grab or running back Aaron Jones' 34-yard touchdown run, but consistency remains elusive.

"We definitely started out pretty fast and through the game had big plays," Jefferson said. "We just cannot go multiple possessions without that energy or getting points on the board. We have to help our defense in some type of way."