SCOTTSDALE, Ariz. -- The pitching education of Mariners right-hander Taijuan Walker continued Thursday, with the Rockies reinforcing the notion the hard-throwing 23-year-old needs to supplement his heat with quality off-speed offerings after getting hit hard in Seattle's 10-8 victory at Salt River Fields.
Walker gave up nine hits and six runs in 3 2/3 innings after the Rockies came out aggressively and ripped three straight doubles to open the game.
"They were only swinging at the fastball and pretty much eliminated every other pitch, so I had to go to Plan B, which I haven't done in a long time," Walker said. "Just throw a lot of curveballs to get them off the fastball. So it was something new today."
• Spring:Tickets | Ballpark | 40-man roster | NRIs
Walker has been working on his curve, but found it to be an even more required weapon on a day his changeup wasn't sharp and his fastball location failed to put the fear in many hitters, either.
"They weren't really swinging at the changeup either," he said. "They were just sitting dead-red fastball. And they're a really good fastball hitting team.
"My location was alright. It wasn't my best. But I took some positives out of it. It's not what I wanted, but it's Spring Training. It's early."
Manager Scott Servais said Walker just needs to keep fine-tuning those off-speed offerings.
"It's the ability to get the secondary pitch, the finish pitch," Servais said. "He got ahead in some counts and really couldn't put them away. The curveball wasn't quite as tight, the changeup wasn't as good as last time out. But we'll keep working and getting ready for Opening Day.

"Some days it's been better than others. Today the cutter, the changeup, the curveball, he didn't really have a finish pitch. Some days that happens."
Walker dominated last spring when he posted a 0.67 ERA in seven Cactus League starts, but then came out of the gate slowly in the regular season before recovering well and posting an 11-8 record and 4.56 ERA in 29 starts. This year his ERA sits at 6.88 after five spring outings, with one more warmup before things get real.
He knows other teams will mimic the Rockies' approach, so his curve must continue to be a priority.
"It wasn't as sharp as I wanted, but it helped a lot," he said. "I threw it in there and you could tell how much they were sitting on the fastball, because they were pulling every single curveball foul or hitting it off the end of the bat.
"If my changeup was sharp, then maybe I'd get out of some jams, get some ground balls and some swing and misses with it. But just forget about this one. Take the positives, learn from the negatives and move on to the next one."
The Rockies hit five doubles off Walker in his 3 2/3 innings. He did manage a 1-2-3 third, but was eventually knocked out by a two-out, two-run double by Carlos Gonzalez on his 80th pitch.
Walker issued just one walk with three strikeouts and has just two bases on balls with 16 strikeouts in 17 innings this spring. But obviously he'll need to mix his pitches better on days he doesn't have electric command with his mid-90s heat, once teams focus on the fastball.
"It happened to me last year, too," Walker said. "But I think if I can start throwing my curveball early and throw it for strikes, then maybe the scouting report will start to say, 'OK, he has a good curveball he's going to throw, so we can't just sit on the fastball. Then I can add my changeup in there, too."