Last week, Justin Davis was at the theme park that claims to be the happiest place on earth.That might be true for the millions who visit Disneyland every year, but for the senior running back at USC out of Lincoln High, the happiest place on earth is where he’ll be this afternoon.

 Davis and the No. 9 Trojans (9-3) will play No. 5 Penn State (11-2) in the 103rd Rose Bowl at 2 p.m. today in Pasadena. Both teams visited Mickey Mouse’s home as part of the festivities leading up the “Granddaddy of Them All” — the game Davis dreamed of playing when he signed with USC.

But after three tumultuous seasons and a 1-3 start this season, hopes Davis ever would play his dream game were slim, to say the least.

“I would never have imagined that I would be playing in the Rose Bowl, especially the way the past seasons have gone,” said Davis, a 21-year-old Stockton native and The Record’s All-Area Player of the Year his junior season at Lincoln. “If you would have told me last year I would be going to a Rose Bowl, I wouldn’t have believed you.”

Last October, Steve Sarkisian was indefinitely suspended as head coach and later fired after he didn’t show up for a scheduled practice and appeared to be intoxicated during a pre-practice meeting with his assistant coaches. It was another blow to the program following the indelicate firing of Lane Kiffin, the coach who signed Davis to USC in 2013. Offensive coordinator Clay Helton took over for Sarkisian as interim head coach and the Trojans finished the 2015 season 9-4 with a loss to Wisconsin in the Holiday Bowl.

This season, Helton was promoted to head coach but quickly found himself on the hot seat when the Trojans were blown out by No. 1 Alabama in their season opener and lost two of their next three. Davis said Helton’s leadership and his decision to start redshirt freshman Sam Darnold at quarterback rejuvenated the team and set USC on course for an eight-game winning streak.

“When the hard times come, like after we lost to Utah, you kind of look to see how your coach is going to react because the players, you’re going to be a little bit lost. It’s going to be hard for you to handle it,” Davis said. “So, you look to your leader and (Helton) just came in and said there’s a whole lot in front of us. His demeanor didn’t change one bit, so just to have that type of leadership and just to have that solid rock as a coach, knowing that he’s going to be the same regardless of whether it’s hard or bad, that was the main factor in our team turning the season around.”

Darnold has thrown for 2,633 yards with 26 touchdowns and eight interceptions in 12 games, including nine starts. Like Helton, Darnold’s even-keeled demeanor was a factor in the Trojans’ resurgence, Davis said.

“He’s definitely a big part of it. The thing about Sam, you wouldn’t think he’s a freshman,” Davis said. “He has the athletic ability. He can extend plays. He has a rocket arm, but it’s all about what’s between his two ears and his composure. You have to be poised as a quarterback. You look into a quarterback’s face and kind of tell if he’s ready for the moment and he definitely is.”

USC’s big moment this season came on Nov. 12 in Seattle when Darnold threw for 287 yards and two touchdowns in the Trojans’ 26-13 win over No. 4 Washington in Seattle. USC finished second in the Pac-12 South and earned an invitation to the Rose Bowl where they will play the Nittany Lions, who have won nine in a row.

Davis said he wasn’t a big USC fan growing up, but he loved college football and he loved watching the Rose Bowl on TV. The 2005 rendition, when Vince Young and the Texas Longhorns rallied in the fourth quarter to upset the No. 1-ranked Trojans is the one he remembers the most.

“That’s the game that everyone will remember,” Davis said. “I remember watching that game and like, man, this game is crazy and it would be even crazier if I had the chance to play in it someday. It does seem like the atmosphere is so electric. The environment was so off the wall. It just seemed like it would be a whole bunch of fun to play in it someday. I’m just glad to be a part of it.”

Davis has been an important part of USC’s running game the past four seasons. The 6-foot, 200-pound quick, darting tailback has rushed for 2,422 yards in his career, putting him 12th all-time at a program that has produced O.J. Simpson, Charles White, Ricky Bell and Marcus Allen. Davis has rushed for 100 or more yards five times, including twice this season, and has 19 career rushing touchdowns and 21 overall. His most memorable performance, he said, came last season against UCLA, when he ran for 130 yards in the Trojans’ 40-21 win that snapped a three-game losing streak to their cross town rivals and gave USC the Pac-12 South title.

“I will always remember the UCLA game because it’s such a special game,” Davis said. “But the Rose Bowl is going to surpass it. No matter what I do in the game, this is the biggest moment.”

 Davis started the Trojans’ first six games this season before an ankle injury sidelined him for three games. He likely will back-up sophomore Ronald Jones II today.

Davis enrolled in college a semester early and recently finished his degree in economics. Davis said despite the coaching tumult during his time at USC, he’s still had a great experience.

“If I could rewind it, I would still go to USC,” he said. “These four years year have meant so much to me. As a person, I’ve experienced so much that I thought I would never ever experience. Obviously, I may have wanted to win a few more games here and there, but just the experience was second to (none) and going to the Rose Bowl is the cherry on the top.”

Following the Rose Bowl, Davis will play in the East-West Shrine Game on Jan. 21 in St. Petersburg, Florida, and then train for a shot in the NFL.

“That’s my next plan in life, to try and get into the NFL,” Davis said. “That’s what I have my mind set on.”