SEATTLE — The puzzle that is Taijuan Walker has yet to be solved.

It hasn’t been stemmed from lack of effort from all parties involved. There have been talks and a demotion to Class AAA. But Manager Scott Servais and pitching coach Mel Stottlemyre find themselves following a similar pattern of frustration as those people who held the same positions before them.

The question is how to unlock the vast potential of the 24-year-old right-hander and build it into a consistent big league performer.

The Mariners thought Walker made a step forward in his previous outing in Chicago, throwing aggressively inside and showing the competitive poise necessary to withstand in-game adversity.

On Saturday night in a frustrating 10-3 loss to the Angels, Seattle saw none of that from Walker in a start that illustrated any perceived progress could be fleeting and unreliable. Meanwhile, Seattle dropped to 69-66 and another game back in the wild card standings.

Walker delivered his worst outing in a season full of disappointment and unmet expectations, failing to get out of the first inning while giving up six runs and serving up three straight homers to Kole Calhoun, Mike Trout and Albert Pujols.

“It was over before it really got started,” Servais said. “Obviously, Taijuan did not have his best stuff. He threw the ball pretty well the last time out in Chicago. I’m pretty surprised by what happened tonight.”

And while the Angels’ pitching is suspect and capable of giving up plenty of runs, there was no crazy comeback this time. That magic trick can’t be performed nightly.

When Servais had finally seen enough and trudged to the mound to pull Walker, a sizable portion of the 20,357 fans in attendance serenaded the situation with boos. Walker exited the pitcher’s mound, eyes fixed at his feet as he marched to the dugout.

“It wasn’t good,” Walker said quietly. “That was pretty much it — just bad all the way around. I felt really good in the bullpen and didn’t transfer over.”

Servais’ goal for his starting pitchers is simple: Give the team a chance to win the game and compete. That didn’t happen.

“He didn’t have much on the ball and didn’t make any real adjustments to try and find it,” Servais said. “I tried to hang with it as long as I could, but it got to the point where we had to go to some of our bullpen guys.”

Walker started off by dotting Yunel Escobar in the left hand with a 94-mph fastball on the first pitch of the game. Escobar had to leave the game with a contusion, but x-rays were negative. Calhoun followed with a disheartening 13-pitch at-bat where he fouled off seven straight pitches on a 3-2 count and then yanked a split-finger into the stands for a 2-0 lead.

“I hit the first batter and kind of lost focus” Walker said. “(Calhoun) battled and I felt like I made some good pitches. Even the homer, it wasn’t a bad pitch.”

Calhoun’s homer made it impossible for Mike Trout to hit a first-inning, three-run homer like he had in three out of his last four games at Safeco. So instead, he hit a solo homer to make it 3-0. It was Trout’s 27th homer of the season. In his career, he is 9 for 11 with three homers against Walker.

But the homer barrage wasn’t done, Pujols sat on a 1-0 fastball and blasted it off the digital scoreboard in deep left-center to make it 4-0.

The carnage continued. Walker did manage to get two outs, but an error from Kyle Seager, a single and RBI doubles from Andrelton Simmons and Escobar’s replacement Cliff Pennington ended his day after 11 batters faced and 43 pitches thrown. Five of the six runs were earned for Walker. Switch-pitcher Pat Venditte came in and got the final out of the inning, drawing a sarcastic cheer from Mariners fans with the bleeding finally stopped.

“Tonight, he just didn’t have it,” Servais said. “You can make up all the excuses you want. He just threw fastballs and it wasn’t big velocity and they got hit, without much of a secondary pitch to complement it.”

Following the game, Walker had text messages waiting from multiple people saying that he was noticeably tipping his pitches and the Angels knew what was coming. He admitted feeling like the Angels’ hitters were a little too ready for certain pitches in certain counts and planned to go over video on Sunday.

Still, he’s 4-10 with 4.60 ERA on the season and is still searching for answers that aren’t easy or evident.

“It’s been frustrating all around,” he said. “It started off good and everything felt fine. I got hurt and after that things have been up and down. I will have a couple good starts and a couple of bad starts. It hasn’t been consistent.”

Seattle has dealt with its share of first-inning deficits vs. the Angels at Safeco, rallying for wins on multiple occasions. When Franklin Gutierrez belted a two-run homer off Angels starter Tyler Skaggs, it seemed possible.

But the Mariners couldn’t stop the Angels from adding to their lead. Pujols hit his second homer of the game, a two-run shot in the second inning to make it 8-2. It was his 28th of the season. Calhoun continued the power display, hitting his second homer of the game in the fourth inning — a solo blast to right field.

Seattle tacked on one more run with a solo homer from Nelson Cruz, his 34th of the season.