KANSAS CITY, Mo. — Heat? What heat? So what that it was 90 degrees when Sunday’s game started at Kauffman Stadium. And then spiked upward.

“This sun here is the same sun there is in Cuba,” said left-hander Roenis Elias, who signed with the Seattle Mariners in 2011 after defecting from his homeland.

“In Cuba, I pitch like that. I have no problem with the heat.”

Apparently not.

Elias outdueled Kansas City’s Yordano Ventura in an intriguing matchup between two rookies. While Elias relies on a curve and change to set up his fastball, Ventura has 100-mph power and a killer slider.

“It was one of those (games),” catcher Mike Zunino said, “where (Elias) was able to throw all of his off-speed pitches, ahead or behind in the count, which kept them off balance.

“They were swinging the bats really well the last few games. We knew we had to throw everything at them to keep them off balance, and he was able to do that.”

Elias yielded only one run and five hits in 62/3 innings before four relievers protected a 2-1 lead over the final seven outs. Elias struck out five and walked two while improving to 7-5 and lowering his ERA to 3.74.

“They got their run (in the second inning),” he said, “and that was it. Everything was working well. Thank God.”

Just like Cuba. Except the pay is better.

“Si,” Elias said with a laugh, “mucho mejor.”

Much better.

Jackson update

Outfielder Alex Jackson, the Mariners’ first-round pick, is scheduled to take his physical examination Monday in Seattle.

Barring something unexpected, a formal announcement of his contract should occur prior to the Mariners’ game against Boston at Safeco Field. Jackson is expected to take part in batting practice.

The Mariners chose Jackson on June 5 with the sixth overall pick in the draft. They previously reached agreements with 31 of their 40 picks, including each of their other top-14 picks.

Jackson, 18, reached agreement last week on a deal that includes a $4.2 million signing bonus. He is expected to be assigned to Peoria in the Arizona Rookie League.

All-Star omen?

Fernando Rodney became the fourth pitcher in Mariners history to reach 20 saves in the club’s first 75 games when he closed out Saturday’s 2-1 victory over the Royals.

Rodney then got No. 21 in Sunday’s 2-1 victory — and that tied him with Royals closer Greg Holland for the American League lead in saves.

The other Mariners closers with at least 20 saves through 75 games: Kazuhiro Sasaki had 27 in 2001; J.J. Putz had 22 in 2007; and Brandon League had 20 in 2011. All three were later selected for the All-Star game.

Seager with the D

Third baseman Kyle Seager aided Rodney’s save on Sunday with two sparkling defensive plays to start the ninth inning.

First, Seager made a charging, bare-handed pickup and throw in fielding a squibber by Salvador Perez for the first out. Next, Seager fielded a soft spinner by speedy Jarrod Dyson for the second out.

“That first play was incredible,” Zunino said. “He’s playing back against a guy (Perez) who can yank the ball and definitely pull it down the line.

“To be able to cover that much ground, bare-hand it and make that play was something else.”

Any bobble or hesitation on Dyson’s ball also likely fails to get an out.

“That’s a tough play,” manager Lloyd McClendon said, “but we’ve seen it time and time again.”

Short hops

The last time Fernando Rodney had three saves in three days was Aug. 11-13, 2012 for Tampa Bay. The first two came at Minnesota; the third one came against the Mariners at Safeco Field. … The Mariners’ last three-game sweep at Kauffman Stadium was May 25-27, 2007. … The Mariners’ only other continuous sweep in a three-game road series came when they opened the season by winning three games over the Angels in Anaheim. The Mariners won all three games against the Yankees in New York, but rain interrupted the series. They won April 29 and May 1 before returning June 2 for a victory from the April 30 rainout. … Mariners starting pitchers have allowed one or no runs in nine of the last 10 games. … Willie Bloomquist went 2-for-3 with two doubles. He has hits on 11 of his 13 starts since May 23. He is batting .383 (18-for-47) in that span.

Minor details

Right-hander Luiz Gohara, one of the organization’s top prospects, began his season Saturday with a dominant performance in the Arizona Rookie League.

Gohara, 17, permitted five hits and one unearned run in 62/3 innings in an 8-4 victory over the White Sox in Peoria, Ariz. He also struck out nine and walked one.

The Mariners signed Gohara, a native Brazilian, on Aug. 12, 2012. He entered the season ranked by Baseball America as the organization’s No. 4 prospect — behind Taijuan Walker, D.J. Peterson and James Paxton.

Looking back

It was six years ago Monday — June 23, 2008 — that Felix Hernandez hit a grand slam against Mets left-hander Johan Santana in 5-2 victory at Shea Stadium in New York.

It was the first grand slam by an American League pitcher in interleague history and the first homer (period) by a pitcher in Mariners history.

“My approach? Just swing. I closed my eyes,” Hernandez said at the time. “I was happy and I was thinking that’s all I need — four runs.”

It was all the Mariners needed, but Hernandez failed to get the victory. He left the game after 42/3 innings because of a sprained left ankle, which he suffered while covering the plate on a run-scoring wild pitch.

On tap

The Mariners open a six-game homestand at 7:10 p.m. Monday with the first of three games against Boston at Safeco Field.

Right-hander Felix Hernandez (8-2 and 2.22 ERA) will face Red Sox right-hander John Lackey (8-4 and 2.96). Root Sports will carry the game.