SANTA CLARA – The 49ers have very little material from which to prepare for Sunday’s home opener against the Detroit Lions.

So coach Kyle Shanahan was forced to go back and relive the disappointment of Super Bowl 51, though he tried to remove all emotions and take a clinical approach to gain information that could be useful this weekend.

There was not much to be gleaned from the Detroit Lions’ season opener on Monday, a game that got out of hand midway through the third quarter. So Shanahan has spent a great deal of time looking back at the history of Detroit coach Matt Patricia, who previously served as the New England Patriots’ defensive coordinator.

That quest for more intelligence sent Shanahan back to Super Bowl 51, when his offense with the Atlanta Falcons went up against Patricia’s Patriots defense.

“You go back to everything,” Shanahan said on "49ers Game Plan," which airs on NBC Bay Area (Ch. 3) on Saturday at 7 p.m.

The Lions and New York Jets were tied 17-17 in the third quarter before the Jets scored touchdowns on a pass play, an interception return and a punt return in less than three minutes to blow the game open and change the approaches of both teams for the remainder of the way.

“You cant just watch 2 ½ quarters of football for the whole week," Shanahan said. "This is stuff I do over the summer, also. Over the summer, we’re not watching Detroit. We’re watching all New England. We’re watching the 2017 year, the 2016 year, and I go back to the last time I played against them, which was in the Super Bowl.”

 

Shanahan’s offense was rolling in the Super Bowl, as the Falcons led 28-3 in the middle of the third quarter. In Atlanta’s first six possessions, the offense rolled up 14 first downs. But Atlanta did not score in their final four series, and managed just three first downs. Shanahan was roundly criticized for leaning too heavily on the passing game in his fourth-quarter play-calling.

The Patriots' defense stiffened, allowing Tom Brady to engineer a comeback for the ages. The Patriots won, 34-28, in overtime. Less than a month later, Shanahan spent considerable time at the NFL scouting combine with Belichick for advice on becoming a first-time head coach and to learn from what happened to him at the Super Bowl.

“Everyone is a product of their environment,” Shanahan said. “It’s a very good scheme. He knows it very well. Matt’s a very good coach. Matt is very bright, and he’s learned from the best.”

Shanahan said he assumes Patricia will use a similar approach with the Lions from his time with Patriots coach Bill Belichick. The Patriots use a variety of defensive fronts and coverages. They are rarely predictable.

“I really look at this game, schematically, it’s more about us, putting ourselves in good positions and doing what we do well,” Shanahan said. “We’ll see their plan as we go. We’ll see it early in the game. We’ll see it all the way through the first half. We’ll see their adjustments at halftime, and we have to be ready to adjust accordingly.”

This Sunday, be sure to watch 49ers Pregame Live at 12 p.m. and 49ers Postgame Live immediately after the game on NBC Sports Bay Area and live streaming on the NBC Sports app. Greg Papa, Donte Whitner, Jeff Garcia, Matt Maiocco and Laura Britt will have everything you need to know from the 49ers’ season opener.