The two people walking with Jason Calliste on senior day were friends from previous lives.

One was Kadeen Thompson, a childhood buddy from Canada, someone Calliste has known since they were in diapers. The other was Carlos Briggs, a former assistant coach at Detroit.

Detroit still has special meaning for Calliste. He spent four years there, scored more than 1,000 points, started almost every game he played. Then everything got crazy: The athletic director resigned, along with an assistant coach. They�d been caught having an affair. Briggs was terminated, too, and filed a whistle-blower lawsuit.

That�s when Calliste knew it was time to go, not that it was easy.

�Everything I know was there,� Calliste said. �If had to call a place home in America, it would probably be Detroit. I came here and had to start over.�

Soon, Calliste will start over again. His stay in Eugene was brief, a one-year basketball residency. Saturday was his senior day, and in homage, Oregon played �O Canada� before the national anthem.

Coach Dana Altman had mentioned the idea earlier in the week. Of course, Calliste loved it.

�That was nice right there,� he said.

That�s how the day began. It ended with a mosh pit, fans streaming onto the court to celebrate Oregon�s 64-57 upset of No. 3 Arizona. The Ducks booked tickets to the NCAA Tournament after scoring the biggest victory of their season, and it�s safe to say neither of those things would have happened without the fifth-year transfer from Ontario.

Calliste scored 18 points and hit four of his five three-pointers. Included in that total were several of Oregon�s biggest baskets: a trey to end the first half, a jumper and foul to give the Ducks their first second-half lead, a three-pointer on the next trip to make it 56-51.

On a team that hasn�t always executed in the clutch, Calliste is the one guy who never seems rattled.

�When the big times come, yeah, I want to take those shots,� he said. �If we lose, it�ll be on me. If we win, it�ll be on the team.�

Calliste isn�t the first player who comes to mind when you think about an MVP of this Oregon team. Joseph Young scores more points. Mike Moser gets more double-doubles. Johnathan Loyd is the spark plug that makes everything go.

Quietly, though, Calliste has been as important as anyone to Oregon�s success. The Ducks don�t beat UCLA if he doesn�t hit a contested three-pointer in the final minutes of regulation. They don�t beat BYU in overtime without his 31 points. They definitely don�t beat Arizona without the shots he hit on Saturday.

The biggest one, in hindsight, was a 19-footer to put the Ducks in front for good. The score had been tied 50-50 moments earlier, a perfectly symbolic toss-up with 5 minutes remaining.

Aaron Gordon hit a free throw to give Arizona a one-point lead. Calliste came back and, with Arizona�s 7-foot center, Kaleb Tarczewski, in his face, fired up a jumper from the left wing.

Calliste crashed to the court. The ball swished through the net. Altman pumped his fist on the sideline, and suddenly you felt pretty good about Oregon�s chances.

�Pretty big (stones) there,� Altman said later, shaking his head.

Watching Calliste play, the phrase that comes to mind is �cold-blooded.� He rarely cracks a smile on the court, or off of it, for that matter. He�s almost frighteningly intense, to the point that the Ducks have to rein him in at times.

That�s a quality this team desperately needed. Calliste has started one game this season � against Washington State, when Damyean Dotson was suspended � but he, more than anyone else, gives Oregon its edge.

�Competitiveness is a great quality,� Altman said. �He�s brought that to us.�

Ask Calliste why he wanted to play at Oregon, and he mentions the other transfers who came before him. He says he knew the Ducks would be good, which has turned out to be true, even if it didn�t look that way five weeks ago.

After starting 3-8 in league play, Oregon won its final seven games to finish 22-8 and 10-8 in the Pac-12. The credit goes a lot of places: to Altman for keeping the team together, to Moser for playing his best basketball down the stretch, to Young and Loyd and Waverly Austin for stepping up at various moments.

But when you�re talking about the most important players on this team, don�t overlook Calliste, even if he�d never say so himself.

�It�s still not about me,� he said. �I just helped. I�m just a part of it.�

A big one, for sure.

Follow Austin on Twitter @austinmeekRG. Email austin.meek@registerguard.com.