The early returns from the 49ers offseason program indicate the success of Kyle Shanahan’s offense will be dependent on the running game, play-action and hitting on deep passes for explosive gains.

That makes new receiver Marquise Goodwin, a former member of the US Olympic track and field team, a key figure for San Francisco.

Goodwin believes he’s the fastest player in the NFL. And his speed was on display last week during a minicamp practice when he streaked past cornerback Keith Reaser, another of the 49ers’ fastest players, for a 50-yard touchdown from Brian Hoyer.

With Goodwin on the outside, defenses will have to account for his ability to stretch the field over the top while being mindful of San Francisco’s emphasis on the running game.

“It makes them scared,” said Goodwin. “You got to honor the speed. You got to get back. It keeps them honest. It makes them stick to their technique to where they don’t really guess on things. They really have to hone in on the actual call on the defense. Everybody has to be hitting on all cylinders. Because if you slip, if you’re flat footed, it’s a wrap.”

Goodwin finished 10th in the long jump at the London Olympics in 2012 before failing to qualify for the Rio games in 2016 despite posting the longest jumps before the US trials earlier that year.

He ran a blistering 4.27 in his 40-yard dash at the combine in 2013. He was selected in Round 3 of the NFL draft by Buffalo but has been hampered by injuries as a pro. Goodwin’s best season came in 2016 when he logged 29 receptions for 439 yards and three touchdowns. Five of his six career touchdowns went 40 yards or longer.

“It’s like the old baseball commercial, ‘Chicks dig the long ball.’ Anytime you throw a deep ball, everybody gets pumped up,” Hoyer said. “The good thing with us is that we have a guy like Marquise, and I’ll even throw a guy like Aldrick (Robinson) in there, just guys who can stretch the defense.

“When I played for Kyle in Cleveland, we had Travis Benjamin and we had Taylor Gabriel so we hit some of those deep balls back then with those guys. What it does is now the defense has to honor the deep ball. So now, we have routes where we send those guys deep and then we break them off and it’s an easy throw.”

The 49ers finished with the league’s last-ranked passing attack last season averaging just 182 yards per game. Shanahan has brought in a new group of quarterbacks that includes no holdovers from last year: Hoyer, Matt Barkley, C.J. Beathard and Nick Mullens.

The receiving corps is nearly as new with Jeremy Kerley as the lone returner among the presumptive five wideouts atop the depth chart: Pierre Garçon, Goodwin, Kerley, Robinson and rookie Trent Taylor.