Lucas Gioloto sat at home all winter, waiting for the phone to ring.

Nearly a month into the season, the call finally came -- from the San Diego Padres.

The veteran right-hander is scheduled to make his season debut on Sunday in Seattle as the Padres will go for a season sweep of the Mariners in their Vedder Cup.

"I've been doing this for a long time. Pitching in the big leagues, being in a rotation, that's normal for me," Giolito said before San Diego's 7-4 victory Saturday. "What I was going through the last few months was more abnormal. I'm glad to be through that and back where I feel I belong."

With pitchers Nick Pivetta, Joe Musgrove, German Marquez and Matt Waldron all out with injuries, the Padres could use another arm.

Giolito went 10-4 with a 3.41 ERA for Boston last season. He's 2-1 with a 4.35 ERA in four career starts against Seattle.

"He's been there, done that," Padres manager Craig Stammen said. "He knows what it's like going through a full season. Pitching well in the big leagues, that's the biggest attribute he brings. He knows how to get outs, get outs in the big leagues."

Giolito signed a one-year deal worth $3 million with the Padres on April 22. He made four minor-league starts in preparation for Sunday.

"I'm just excited to be back out there and help a really good team win baseball games," he said. "It was kind of a surreal offseason, leaking into spring training and the season. But I'm really appreciative of the Padres giving me the opportunity."

Walker Buehler pitched five innings for the victory Saturday. He was backed by homers from Nick Castellanos, Gavin Sheets and rookie Rodolfo Duran, whose two-run shot in the seventh inning was his first major-league hit after going 0-for-10.

"If you play baseball, if you want to be a major leaguer, you always think of that, you have dreams about it," said Duran, a catcher who spent 11 years in the minors before being called up earlier this month. "Now that I was able to do it, it's amazing."

The Mariners have lost three of their past four games since getting within a game of the .500 mark. They've been above .500 for one day all season, when they were 3-2 on March 30.

"I think we know we're not playing all the way to our capabilities, but it's a long year," said Logan Gilbert, who allowed a season-high seven runs Saturday. "Every single year I've been here, we've had that. The biggest thing is not to panic. Second thing is, how quickly can you turn it? Because things like this are going to happen to every team, every single year, it's just how much can you shorten that window and get back to playing your best baseball."

The Mariners are set to send right-hander George Kirby (5-2, 2.84 ERA) to the mound Sunday. He defeated host Houston 3-1 Monday when he allowed one run on seven hits over five innings, with two walks and seven strikeouts. Kirby is 0-2 with a 10.38 ERA in two previous starts against the Padres.

The Mariners hope to have third baseman Brendan Donovan and catcher Mitch Garver back after both were late scratches Saturday. Donovan needed a rest as he recovers from a groin strain and Garver had back tightness.