About 15 months ago, quarterback Drew Allar chose to return to Penn State for his senior season, hoping to chase a national championship and solidify his NFL Draft stock as a top pick.

Nothing went quite as he’d imagined.

The Nittany Lions had a disastrous season leading to coach James Franklin’s firing, and Allar was sidelined by an ankle injury that ultimately needed surgery. But as he attended the NFL combine this past week, Allar said he had no regrets about his decision.

“Obviously, it’s not what I envisioned,” Allar told reporters in Indianapolis. “I’m a firm believer in everything happens for a reason. I’ve just taken this opportunity through this injury to better myself, both as a person, a teammate and as a player. So, I wouldn’t change a thing. … I know everything’s gonna work out for the best in the long run.”

Allar fractured his left ankle in a mid-October loss to Northwestern and missed the Nittany Lions’ final seven games. The injury and a down season overall dropped Allar from a trendy first-round pick in the upcoming April draft to maybe a mid-round option.

But Allar hasn’t lost his confidence. Among the 16 quarterbacks invited by the NFL to this year’s event, Allar said his arm is still the best.

“I’m not saying that out of cockiness or anything like that,” said the 6-foot-5, 228-pounder. “It’s just something I truly believe in. And I knew this (combine) opportunity would come around for me, hopefully, so I was just trying to prepare myself to put myself in a good position to go out and throw.”

Allar, who turns 22 on Sunday, said his motivation in the months since the injury was getting himself ready to throw in front of coaches and scouts at Lucas Oil Stadium. NFL analysts questioned some errant throws in Indianapolis, but he also tossed accurate deep balls that surely helped his cause.

“As soon as I really got back to school and started my rehab process, my whole focus … has been getting to this point, being healthy enough to have the chance to put myself out there and throw,” said Allar, adding that he was excited to get out there “and just cut it loose.”

Allar earned endorsements at the combine from former teammates who marveled at his arm strength but also praised his intangibles.

“He has an arm, for sure,” tight end Khalil Dinkins said. “He can throw that (ball) 90, 80 yards. I’m definitely exaggerating, but the way he sees the game, he’s a smart player.”

Former teammate Zane Durant agreed.

“You know he can sling the ball,” said Durant, a defensive tackle. “I just want him to go out there, showcase who he is and what he’s going to do (in the NFL).”

Allar didn’t run the 40-yard dash, so NFL teams didn’t see him test the ankle outside of his throwing session. But Allar declared himself fit enough to compete, if needed.

“If I had to play a game today or tomorrow, I feel like I could go out there and get it done,” he said.

In six games last season, Allar completed 103 of 159 passes for 1,100 yards, eight touchdowns and three interceptions. He finished his four-year Penn State career with 7,402 passing yards and a strong 61-to-13 ratio of touchdowns to interceptions — a double-overtime INT against Oregon notwithstanding.

He made 35 career starts at Penn State.

“Allar looks the part with prototypical size and an effortless arm that can make any NFL throw,” wrote draft analyst Lance Zierlein in the quarterback’s NFL.com profile.

But Zierlein went on to say Allar looked good running a conservative offense earlier in his Penn State career, but his play “became more erratic once the playbook was opened up and more responsibility was put on his plate.”

Last summer, Allar was touted by draft gurus as a top-10 pick but now projects as a possible Day 2 selection. Among quarterbacks, Allar ranked third behind Indiana’s Fernando Mendoza and Alabama’s Ty Simpson, according to ESPN analyst Mel Kiper’s latest list.

Mendoza, considered the likely No. 1 overall pick in April’s draft in Pittsburgh, chose not to throw at the combine. But Allar was joined on the field by Simpson, Carson Beck of Miami (Fla.), LSU’s Garrett Nussmeier, Clemson’s Cade Klubnik, Kansas’ Jalon Daniels and Vanderbilt’s Diego Pavia.

“It’s not just me in this quarterback class,” Allar said. “There’s a lot of other talented quarterbacks that have been cool to get to meet and create a relationship with them. So, it’s been a fun process through January up until now.”