Why are there no Super Bowl commercials? Here’s what we know so far…

On the heels of Super Bowl LI, NFL.com examines how the ratings have been lagging behind.

The following are the biggest storylines heading into the first Super Bowl game on Sunday, Jan. 3: — NFL ratings have dipped 0.7% since the season opener, the lowest in NFL history.

NFL.COM: The league’s biggest-ever ratings drop in 2017 is a sign of how difficult it has been for the league to stay relevant, even with new stadiums and new TV deals.

— Super Bowl-related ads will debut in the first half of the game on the Super Bowl LII commercial, which features the NFL’s commissioner, Roger Goodell, and former Patriots head coach Bill Belichick.

The commercial will air at 6 p.m.

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— New England Patriots quarterback Tom Brady has taken heat for comments he made during the 2016 NFL season about his wife, Gisele Bundchen, who was diagnosed with Hodgkin lymphoma, a disease that can lead to cancer.

Brady has defended his comments in the wake of Bundchen’s diagnosis.

— Brady is the first quarterback to lead the Patriots since 2000, when Tom Brady was a member of the New England Football Club.

— Patriots wide receiver Julian Edelman has been suspended three games by the NFL for violating the league’s personal conduct policy.

The Patriots announced that Edelman is suspended indefinitely.

— The NFL has suspended Patriots tight end Rob Gronkowski for six games for violating its policy against domestic violence.

The NFL said it has suspended Gronkowski because of a previous incident in which he was charged with domestic violence in April 2017.

— Bengals cornerback A.J. Bouye has been fined $50,000 for violating a league-imposed five-game suspension.

The commissioner’s office said Bouye did not comply with the team’s terms.

— Former 49ers quarterback Colin Kaepernick has been indefinitely suspended by the team for a second violation of the NFL personal conduct policies, per a league source.

— Jaguars running back Maurice Jones-Drew is expected to miss Sunday’s game due to a torn ACL suffered in a game against the Packers on Dec. 29.

Jones-Skins coach Jim Tomsula said Jones-Wade will not play Sunday.

— Steelers wide receiver Antonio Brown will miss the team-wide anthem after kneeling during the national anthem before the Packers game.

The Steelers have suspended Brown for two games.

— Broncos cornerback Chris Harris Jr. will be unavailable for Sunday’s matchup with the Jaguars due to an undisclosed injury.

— Ravens running back Justin Forsett is likely to miss the game with a knee injury.

The Ravens said Forsett was not wearing his cleats on the sideline during the anthem.

— Rams defensive end Greg Robinson will miss Sunday night’s game with an ankle injury, according to a source.

Robinson did not practice Thursday and did not report to the team facility.

— Texans cornerback Kareem Jackson, who had surgery for a torn Achilles tendon, has been placed on injured reserve, according a source with knowledge of the decision.

Jackson, a seventh-round pick by the Chargers in the 2016 draft, was expected to be a significant contributor in 2017.

He had seven sacks in the preseason and finished the year with one sack and five tackles for loss.

— Raiders cornerback Ronald Darby will miss Monday night’s tilt against the Texans after undergoing surgery for his torn ACL, according an NFL source.

Darby has not practiced this week.

— Jets running back Bryce Brown, who missed all of the 2017 season with a hamstring injury, is expected back for Sunday against the Jaguars.

Brown missed the Jets’ first two games after undergoing knee surgery.

— Saints defensive end Anthony Hargrove will miss Thursday night’s matchup against the Browns with a right knee contusion, according of a source who spoke to the New Orleans Star-Ledger.

Hargrotve was sidelined for a month with the injury, but returned to the field after missing four games due to knee injuries.

The Saints placed Hargrothve on injured reserved, meaning he is eligible to return if he completes his rehab program.

— Eagles defensive end Mychal Kendricks will miss his second consecutive game with concussion symptoms after being injured Sunday against San Francisco.

Kendricks missed the first three games with a broken foot.

— Browns running back Trent Richardson is expected for a MRI exam Sunday night, according the Cleveland Plain Dealer.

Richardson had three carries for 12 yards and a touchdown on Saturday against the 49ers.

— Falcons wide receiver Julio Jones will not return to practice on Monday due to ankle soreness.

Jones was ruled out on Monday with ankle sprain.

Jones is listed as questionable for Sunday.