SEATTLE -- Alec Marsh has come back from the injured list fast. Literally.

On Wednesday, Marsh made his second start since returning from the injured list. And while the second-year right-hander had to battle his way through deep counts and long at-bats in a 4-2 loss to the Mariners at T-Mobile Park -- finishing his outing with two runs (one earned) allowed in five innings with seven strikeouts -- he did so by continuing to lean on his four-seam fastball more than before.

“He was really good,” catcher Freddy Fermin said. “He was gassing, he was pounding the strike zone. He was executing pitches.”

In his first five starts of the season, Marsh threw 131 four-seam fastballs -- throwing the four-seamer 31.7% of the time -- and got 15 whiffs on it.

In the two games since returning from the IL, Marsh has gone to the four-seamer 43% of the time. He has generated 19 whiffs on the heater in those two starts, with a career-high 10 last Friday against the Angels and nine more Wednesday.

“Just good locations on it,” Marsh said. “I know where it plays best, and that’s usually at the top of the zone. Trying to keep it up there and challenge guys late. They think I’m going to go to spin or offspeed stuff, but it’s like ‘I’ve got a good heater, so I’m going to show it to you and try to get you out on it.’”

The increased share of four-seamers has gone hand-in-hand with a rise in velocity. Before going on the IL, Marsh was averaging 93.6 mph on his fastball. In the past two starts, he’s cranked that up to 94.6.

In his first five starts, Marsh hit 96 mph three times. In the past six days, he’s done so nine times.

And not even a strange delay could slow him down.

In the top of the fifth inning, home-plate umpire Jim Wolf took a foul tip off the face mask. He finished off the frame, but when the Royals came onto the field to warm up for the bottom of the inning, he had a long discussion with the rest of his crew. After talking with a Mariners trainer, Wolf eventually left with concussion symptoms.

That prompted a lengthy delay while first-base umpire Ryan Blakney went into the locker room to don his own gear, during which Marsh and Fermin went back into the dugout to get off their feet.

When the bottom of the fifth finally began after a 15-minute delay, Marsh went right back to the hard stuff, throwing seven four-seamers in a 17-pitch inning. That included a stretch of four in a row to Julio Rodríguez which featured Marsh rearing back to hit 96.9 mph on the radar gun.

“He’s a tough out,” Marsh said. “For me, we were down one or two runs at that point, the fastball’s feeling good and I’m going to start challenging you -- and I’m not going to give you anything else until you prove you can hit it.”

Marsh’s day started out as a slog, with the righty needing 39 pitches to get three outs in the second inning. The Mariners only tagged him for one (unearned) run in the frame, when Adam Frazier was tagged with a two-out error at third after he was unable to handle a ground ball.

After that, Marsh retired nine of the final 11 batters he faced, though Ty France doubled the Mariners’ lead with a solo home run in the fourth.

“He stayed in there, he battled, kept them to two runs and gave us a chance to win,” Royals manager Matt Quatraro said.

On the other side of things, though, the Kansas City bats couldn’t make the most of that chance. The Royals put the tying run in scoring position with less than two outs in both the sixth and eighth innings, but both times had to settle for just one run when they needed two.

Kansas City, which entered Wednesday batting .299 with runners in scoring position this season, went 1-for-9 in the final four frames.

“You’ve got to try to capitalize,” Quatraro said. “You know they’re going to be generally low-scoring games when you play these guys; they have a good pitching staff. We put ourselves in a couple spots to do some good things, but they’re trying to get you out. They’re not just laying it in there for you to get them in. Sometimes you execute, sometimes you don’t.”