SURPRISE, Ariz. -- The Mariners continued their slugging ways Thursday with four home runs in two games on a split-squad day, including two by young infielder Stefen Romero in Seattle's 12-2 victory over the Royals.

Romero had a highlight-reel day with a grand slam and a three-run shot in a 4-for-5 game with seven RBIs and a double as well.

Casper Wells also ripped a three-run shot in that game, while Robert Andino homered in the Mariners' 7-3 loss to the A's in Phoenix in the other contest. The four home runs gave Seattle 30 in 14 games this spring, two more than they totaled in the entire 26-game Cactus League schedule last year.

Romero unloaded the bases in the fourth inning against Royals reliever Guillermo Moscoso and then capped things off with a three-run shot off Minor Leaguer Anthony Ortega in the ninth. The 24-year-old second baseman out of Oregon State hit 23 homers a year ago while batting .352 as he split his season between Class A High Desert and Double-A Jackson.

"Yesterday, I was 0-for-2 with two strikeouts," Romero said with a smile. "You just have to flush it. You have to have a short-term memory and luckily today everything went my way."

Romero is hitting .500 (7-for-14) this spring while soaking up his first Major League camp. He's a long shot to find a roster spot with the Mariners this spring, but is certainly opening some eyes as to his potential.

"It's an awesome experience, being around the older guys like [Raul] Ibanez, [Michael] Morse, [Kendrys] Morales," he said. "You just have to take bits and pieces of their game. Especially [Jay] Buhner today in the dugout, he always has a positive mental attitude and it just rubs off on the team. It's a great experience."

Iwakuma more confident, relaxed in camp

SURPRISE, Ariz. -- Right-hander Hisashi Iwakuma threw three scoreless innings of one-hit ball in Thursday's 12-2 victory over the Royals as he continued a strong start to his second spring with the Mariners.

Iwakuma, 31, knows he's part of Seattle's rotation plans this spring and the former Japanese standout appears much more settled in his Cactus League outings this year.

He's allowed just three hits and one run in six innings over his first three appearances, with no walks and three strikeouts.

"I feel a lot stronger this year," Iwakuma said through translator Antony Suzuki. "I came prepared. Last year was a little different story for me. This year, I know I'm in the starting rotation, so I started a lot earlier than I did last year and that's helped me a lot."

Iwakuma replaced Felix Hernandez in the third inning and shut down a Royals team that was unbeaten in its first 12 games this spring. After a one-out double by Alex Gordon in the third, Iwakuma retired the last eight batters he faced.

"I felt great today," he said. "I thought I pitched in a good rhythm, I got in a good groove and was able to keep balls down in the strike zone. The outs were mostly all groundouts, so that's a good sign."

Iwakuma and Hernandez pitched against the Royals on the split-squad day since Seattle wanted to keep them away from division-rival Oakland in the other game. Pitching coach Carl Willis liked what he saw from both and acknowledged that Iwakuma is much better this spring than last.

"He's stronger," Willis said. "He's pitching with a lot of confidence. We saw so many ground balls today and a good curveball as well, which was very good to see."

Hultzen feeling fine, gearing for bullpen session

PEORIA, Ariz. -- Mariners left-hander Danny Hultzen, who has been sidelined since Monday with a mild strain in his right hip, played catch on Thursday and will throw an easy bullpen session on Friday as he works his way back toward game action.

Hultzen, one of the team's premier pitching prospects, was scratched from Monday's start against the Rockies after experiencing some soreness during conditioning drills last weekend.

"We're shooting for a light bullpen session [Friday]," pitching coach Carl Willis said. "If that goes well, we'll give him a day and then a normal bullpen the following day and then transition him back into games. He's much better."

Hultzen, the No. 2 overall selection in the 2011 First-Year Player Draft, never considered the injury serious, but took precautions rather than aggravate the situation. He said he's felt better every day since the initial pain and is confident everything is fine.

"I wasn't expecting it to be any longer than this," he said. "I'm just glad everything has gone smoothly."

Hultzen split last season between Double-A Jackson and Triple-A Tacoma, going 9-7 with a 3.05 ERA in 25 starts in his first professional season.

The former University of Virginia standout is 1-0 with three scoreless innings in two outings this spring, allowing one hit, two walks and six strikeouts.

Worth noting

• Former Mariners catcher Dan Wilson arrived on Thursday to work with some of the young catchers in camp, joining Jay Buhner and Ken Griffey Jr. All three are expected to help out for a few days. Edgar Martinez, who has done the same in previous years, isn't expected this season due to time conflicts with his business schedule.

• Hector Noesi is now scheduled to start Friday's game against the A's in Peoria and pitch the first two innings, followed by a series of relievers that will include Kameron Loe and Chance Ruffin.

• Jon Garland, attempting to make the rotation as a non-roster invitee, gets his third start of the spring on Saturday when the Mariners travel to Glendale to face the Dodgers. Garland, who has yet to allow a run in three innings, is scheduled to throw the first three frames in that game.

Left-hander Joe Saunders, one of the club's expected starters, will follow Garland and throw another three innings.

• The Mariners have added a "B" game to their schedule, traveling to Goodyear to face the Indians next Thursday at 10 a.m. PT.

• This weekend's three games -- on Friday through Sunday -- will be broadcast live on 710 ESPN Seattle at 1:05 p.m. MT (12:05 p.m. PT). The next televised game will be Sunday, March 17, against the Rangers at 1:05 p.m. PT on ROOT Sports. Fans can also watch on MLB.TV.