MANKATO, Minn. — Andrew Sendejo opened the mailbox one day this spring and found it overflowing with envelopes from Rice University, his alma mater.

“I was thinking they were all my parking tickets,” the Minnesota Vikings strong safety said. “They finally found my address.”

Ah, but Sendejo didn’t need to worry. This was a much better haul: a hand-written thank-you card from every player on Rice’s roster in appreciation of Sendejo’s gift to the program for a nutrition center in his name . Coach David Bailiff, who took over the Owls in 2007 for Sendejo’s second season, directed the gesture.

“I thought it would be right to donate more than just the minimum,” said Sendejo, whose contribution became a part of a new facility for the football team that opened last year , one he hoped would inspire other alumni donations. “You need to take it upon yourself to give back. Rice is a special place. You really appreciate it after you’re done.”

The Vikings have gradually grown to appreciate Sendejo, too. For once, they’re not actively seeking competitors for his spot in the starting lineup next to Pro Bowl free safety Harrison Smith.

“He’s a true professional. He’s very consistent, day in and day out,” defensive coordinator George Edwards said. “You know what you’re getting with him. So that’s a credit to him with his accountability, to not only his teammates but to us as far as what we try to do schematically.”

Sendejo was a standout at Rice, totaling eight interceptions, two touchdown returns and 201 tackles over his sophomore and junior years, the latter a 10-win season in 2008 that was the program’s first in 59 years. His senior season was limited to seven games because of a severe ankle injury, though, and he was not drafted. He even had to spend some time in the now-defunct United Football League, with the Sacramento Mountain Lions under former Vikings coach Dennis Green.

Sendejo eventually caught on with the Dallas Cowboys in 2010 before a stint with the New York Jets in 2011 that preceded his discovery by the Vikings primarily for special teams purposes.

In 2013, Sendejo first cracked the lineup after an injury to Jamarca Sanford and wound up third on the team with 104 tackles despite getting only 10 starts. The following year, coach Mike Zimmer’s first season with the Vikings, Sendejo was beaten out by Robert Blanton for the job until filling in for injury the final three games. But his grip on the spot hasn’t slipped since then, despite the team’s consideration of Blanton, Antone Exum, Anthony Harris, Jayron Kearse and Taylor Mays at various points over the last three years.

Prior to the 2016 season, Sendejo signed a four-year contract extension worth as much as $16 million to keep him under team control through 2019.

“The big thing is that he pays attention to all of the little details. He’s going to do everything,” Edwards said. “When you say he’s a professional: He’s going to eat right, he’s going to take care of his body, he’s going to get rest, he’s going to be in the playbook. We can go from the classroom to the field. You’re going to see it, you’re going to hear it exactly the way that we put it in, and I think that makes everybody around him comfortable.”

Sendejo is a free-spirited type of person who once for charity repelled down a skyscraper in Austin, Texas, where he lives in the offseason. Last year, for fun, he connected with Uber to travel around for a promotional tryout as a taxi driver.

There’s plenty of time left to work out and eat right, though.

“Football takes a toll on your body,” Sendejo said, “l so I just try to get any leg up or help that I can.”