Michael Pineda continues his bid to make the Mariners' starting rotation

SURPRISE, Ariz. — One day after his worst statistical outing of the spring, Michael Pineda saw his path to the big leagues grow a little more clear.

The Mariners on Thursday officially eliminated another would-be Pineda competitor from contention for the final rotation spot by reassigning knuckleballer Charlie Haeger to minor-league camp. Unofficially, Haeger was eliminated a while ago because injuries have limited his innings this spring, but still, the number of actual bodies standing between Pineda and his big-league dream is dwindling rapidly.

Mariners officials have privately suggested the job is Pineda's to lose and that left-hander Luke French is the only pitcher with a shot at taking it away from him. The one way Pineda can blow this thing is by failing to establish secondary pitches beyond his fastball, something his manager insists the pitcher did even in taking somewhat of a pounding the other night.

"The way he was using his secondary stuff, it was as good as we've seen it all spring," Mariners manager Eric Wedge said.

Pineda's slider looked vastly improved in terms of the break on it and his ability to land it for strikes.

But it was an at-times-spotty-looking change-up that could eventually decide whether Pineda makes the team and how much major-league success he has early.

The reason for that is that the changeup will likely be Pineda's primary weapon against left-handed hitters.

Everyone knows Pineda can get right-handers out.

In his two-plus months of Class AAA ball last season after a July promotion, he held right-handed hitters to a .190 batting average and a 3.48 earned-run average. But the left-handers gave Pineda some trouble: batting .265 off him and sending his ERA shooting up to 6.28.

A big reason for the disparity was Pineda lacking an effective changeup that can break down and away against southpaws. Sliders are known to be more useful in getting right-handed hitters out compared to lefties.

For a pitcher like Pineda, armed with a 97 mph fastball, the best "out" pitch against lefties would be a changeup that breaks down and away and throws off the timing of hitters trying to catch up to him. Problem is, the changeups Pineda did throw last season often came in too firm and weren't slow enough compared to his fastball to throw anyone's timing off.

On Wednesday night against the Milwaukee Brewers, Pineda gave up four doubles and a triple among the three runs — two earned — and seven hits tacked on to his line over four innings. Three of those doubles came off the bat of lefty hitter Rickie Weeks, while southpaw George Kottaras had the triple.

Pineda had been working on making his changeups slower against lefties. He's reduced his arm action ever so slightly, hoping to knock a few miles per hour off his velocity.

Against the Brewers, it was a mixed bag. Early on, the changeup was staying up in the zone and making for a big fat target.

"I threw too many strikes," Pineda admitted.

Later on, in the third and fourth inning he worked, the changeup came in with a marked difference in speed and drifted down and away.

Wedge noticed the difference right away.

"You just look at the swings," he said. "You look at the reaction of hitters. Hitters can always tell you so much. You look at whether they're taking a pitch, or whether they're swinging, or maybe just a little reaction up there. I think we saw all that."

And the Mariners will want to see more in Pineda's final two starts of the spring.

They can overlook all the hits he gave up, some of them on the trademark fastball he also left too high in the zone. But they will want to be sure he has the confidence to rely on his change-up and slider when needed against big-league hitters far more prepared and dangerous than some of what Pineda has seen down here.

Still, at this point, the Mariners feel his improving secondary stuff is already enough to get him by early on as he builds toward something better. They figure the work-in-progress Pineda represents is still a better option than French — who has also had his issues — while David Pauley has not been built up enough to start.

Pineda knows the rotation vacancy is staring him in the face.

"Yeah, I'm thinking about it," he said. "I'm working hard every day."

And the Mariners are monitoring his progress closely, looking for the positive signs Wedge saw. At the rate Pineda's going, imperfect as it may be, it's probably already enough to pencil him in for April.

NOTE

• Felix Hernandez got roughed up a bit by Kansas City on Thursday night, yielding six runs — three earned — on nine hits over four innings. Hernandez gave up a solo homer to Billy Butler and also got tagged with a wild pitch and a two-base throwing error during an aborted pickoff attempt.

"I feel pretty good, I feel strong," Hernandez said. "I've been throwing a lot of strikes. I think I need to throw more balls because they were hitting everything."

Still, Hernandez struck out seven batters and proclaimed himself on target to take the mound on opening day.

Four of the Royals' hits off him were infield singles.

• Mariners closer David Aardsma played catch on flat ground Thursday with catcher Miguel Olivo at the team's Peoria training complex. Aardsma will likely miss several weeks in April, though Olivo is recovering nicely from a groin injury and could be back earlier than first expected.

• The Mariners cleared up their pitching picture a bit on Thursday, optioning reliever Dan Cortes to Class AAA and reassigning Manny Delcarmen to minor-league camp. Both had been in the running for a bullpen job. Seattle also assigned pitchers Chris Smith and Haeger to minor-league camp.

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com.

Read his daily blog at www.seattletimes.com/Mariners