Chris Smith is one American Sign Language class away from completing his sociology degree at UC Riverside. The problem? The course, offered only in the fall, conflicts with his professional-baseball schedule.

“If I’m delaying it,” Smith said, “I’m doing something right.”

After a six-year hiatus from the majors, including a stint out of baseball, Smith, 35, is intent on relishing every relief appearance he makes. He pitched a shutout ninth inning Sunday. In three appearances over eight days, he has allowed two earned runs on four hits in five innings. He has struck out five.



Manager Bob Melvin appreciates that Smith, who has started 152 of his 301 career minor-league games, can go between short and long appearances if necessary. Perhaps just as important for a losing club in mid-August, Smith reminds teammates of the joy of being on a major-league roster.

“For a guy who hasn’t been here in a while, he certainly doesn’t look like he’s nervous,” Melvin said. “It’s great to see a guy who is that appreciative of an opportunity again.”

In 2011, after getting cut by the Mariners while in Triple-A, Smith returned to his hometown of Hesperia (San Bernardino County). He re-enrolled at UC Riverside and helped the Highlanders as an undergraduate assistant coach. Figuring his pro career was over, Smith planned to earn his degree and apply for UC Riverside’s open pitching coach job.

The Wichita Wingnuts of the independent American American Association invited him in spring 2013 to pitch again. After a strong showing with the Wingnuts, he signed in 2014 with the Sugar Land Skeeters of the independent Atlantic League — a higher level of competition — and went 6-0 with a 2.15 ERA in eight starts.

It was enough to earn a minor-league deal with the Padres. Smith, a nonroster invitee with the A’s this spring, was 6-8 with a 3.93 ERA in 22 starts at Triple-A Nashville before getting called up.

“I was surprised at first,” Smith said. “Then, it was like, ‘OK, that was quick.’ I mean, sure, it was six years. But it felt quick.”

Briefly: Jesse Hahn (shoulder) will make a rehab start Tuesday for Triple-A Nashville. Melvin said he hopes Hahn will need only one start before rejoining the A’s. … After throwing from 105 feet Saturday, Henderson Alvarez (shoulder) threw from 120 feet Sunday.

Connor Letourneau is a San Francisco Chronicle staff writer.

On deck

Monday

at Rangers

5:05 p.m. CSNCA

Detwiler (1-0) vs. Perez (7-8)

Tuesday

at Rangers

5:05 p.m. CSNCA

Triggs (0-1) vs. Harrell (1-0)

Wednesday

at Rangers

5:05 p.m. CSNCA

Manaea (4-7) vs. Darvish (3-3)

Leading off

DL blues: The A’s have used the disabled list an Oakland-record-tying 25 times.

— Connor Letourneau