SAN FRANCISCO — They experienced the worst of times on defense as underclassmen.

And now they believe the best of times are ahead for Oregon with quarterback Justin Herbert returning next year.

The senior class, including some of Jim Leavitt’s key starters, are determined to share a bowl victory together on their way out.

Outside linebacker Justin Hollins, a fifth-year senior, is the only player on the Ducks’ roster who participated in the historic Rose Bowl victory over Florida State on Jan. 1, 2015.

Oregon blew a 31-point lead during the stunning Alamo Bowl loss against TCU to cap the 2015 season, did not qualify for a bowl after a 4-8 finish in 2016 and lost the Las Vegas Bowl following the tumult of Willie Taggart’s abrupt departure and Mario Cristobal’s promotion in 2017.

The Ducks will try to end the postseason victory drought against Michigan State in the Redbox Bowl on Monday at Levi’s Stadium in Santa Clara, Calif.

“We’ve been through a lot,” senior defensive end Jalen Jelks said. “It’s been a long journey. Been through a lot of great teams, bad teams, stuff like that. I can tell you just from the time I’ve been here with coach Cristobal, this program is probably going to be on the rise like I’ve never seen before.

“So in the coming years, I’m definitely going to come back to see some games and see what the Oregon Ducks are going to do.”

Even among the seniors there is a buzz about what’s ahead for the program with the potential of returning all 11 starters on offense and adding a top-five recruiting class for fall camp.

“The way coach Cristobal has recruited, the guys he’s bringing in, the guys that are coming back, having seen how we go about practice and all those things, the sky is the limit for these guys,” senior safety Ugo Amadi said. “I give it two or three years, these guys could win the national championship. You’d be surprised what coach Cristobal has up his sleeve.”

This week the defensive leaders are rolling up their sleeves and putting in the work the beat the Spartans.

In addition to Hollins, Jelks and Amadi, senior inside linebacker Kaulana Apelu hopes to be back in the starting lineup after missing the final three games of the regular season with a fractured leg.

“I think if you know Lana, you know what an awesome presence he is in every way, shape or form imaginable,” Cristobal said of Apelu’s return. “Having him back has been a huge boost. You especially feel it in practice because he does have that kind of juice and that kind of energy. He gets everybody going.

“Everyone knows that everything about him and from him comes from the heart.”

Hollins is one of only 13 players in the country this season with five sacks and four forced fumbles. He leads the Ducks with 12.0 tackles for loss.

Jelks, who has faced more double-teams this season after a breakout junior campaign, has 3.5 sacks and 7.5 tackles for loss in 11 games. He is ready to start at defensive end after missing the regular-season finale at Oregon State due to injury.

Amadi, who started his career at cornerback, is the only player from a Power Five conference with two interceptions returned for touchdowns and a punt return returned for a touchdown this season.

Despite playing in only nine games, Apelu is still second on the team with 58 tackles.

Backup safety Mattrell McGraw and running back Tony Brooks-James, who is not expected to play in the bowl due to injury, are the only other remaining members of Oregon’s 2014 recruiting class.

“Those are tremendous guys. We couldn’t have had the season we’ve had without them,” safties coach Keith Heyward said after Saturday’s practice at City College of San Francisco. “After the game, I will definitely think about all those guys who are leaving. It’s going to be tough replacing them.

“They’ve done a lot for our program, and we’re thankful for that, but we’ve got one more to go.”

Oregon is allowing 27.0 points and 390.5 yards per game in Leavitt’s second season as defensive coordinator.

The Ducks were among the worst defenses in the country under Don Pellum in 2015 (37.5 ppg, 485.3 ypg) and under Brady Hoke in 2016 (41.4 ppg, 518.4 ypg)

Leavitt’s crew will have a chance to finish on a high note against a Michigan State offense that ranks 122nd in scoring (19.8 ppg) and 117th in yards (343.0 ypg) among 130 FBS teams.

“It will be a good matchup. They’re a run-down-your-throat type of team,” Hollins said. “They’ve got one of the best defenses in the nation and they have the best run defense in the nation. It will be a good one to watch.”