SEATTLE -- If the 98-mph fastball and pinpoint control weren't enough, James Paxton sounded a note that should be a warning signal to upcoming opponents.
"I'm healthy," the big lefty said after firing 5 1/3 scoreless innings Wednesday in a 5-0 win over the Rockies in his first game off the disabled list. "It's good to be back out there."
Paxton has emerged as one of the American League's top starters this year, improving to 4-0 with a 1.26 ERA in seven outings. He missed more than a month with a strained left forearm, but his return- - the first of four injured starters now back -- bolstered the Mariners hopes as they won their fourth straight to improve to 25-29.
"We're starting to get some big pieces back," said catcher Mike Zunino.
And none may prove bigger than Paxton, who has developed into a "top of the rotation stud," in the words of manager Scott Servais.
"I can't say enough about what it means to have Paxton back," Servais said. "He gave us more tonight than we expected, having not pitched in a little over a month. At this level, it was awesome."
Paxton came out firing with a 1-2-3 first with 12 of his 14 pitches going for strikes and his fastball consistently sitting at 98.
The big lefty gave up an infield single to Tony Wolters with two out in the third and Wolters took second on a throwing error on Kyle Seager after the third baseman gloved the hard grounder to his right with a diving stop. Paxton then balked Wolters to third, but stranded him there by getting Charlie Blackmon to ground out to Robinson Cano.
From there, he breezed until a pair of one-out singles in the top of the sixth led Servais to pull the plug after 74 pitches, not wanting to overextend Paxton in his first start back.
Of Paxton's 41 pitches in the first three frames, 35 were strikes, and he wound up throwing just 17 balls in his entire outing.
"Unbelievable," said Zunino. "It was like he didn't miss a beat. He's a competitor and that's the biggest thing. When a guy is not afraid to throw to contact and attack guys, that's what you can get out of him. He was spot-on with his location and all his off-speed stuff."

Paxton said his rehab stint gave him extra time to work on his mechanics with pitching coach, Mel Stottlemyre Jr.
"It was nice to just hop back out and feel that comfortable again on the mound," he said. "Being able to throw strikes was huge, getting ahead of guys and working with Mike again. He just makes it so comfortable for me back there. I really trust him a lot. He does a great job with me."
Servais noted his team felt a big boost having one of its main horses back on the mound and has started to build a little momentum now with four straight wins against the Red Sox and Rockies.
"We're feeling good as a team," Paxton said. "We've been playing really well here this last little bit, especially against Colorado. Guys are putting together some really good at-bats, the bullpen has been great, the starting pitching has been good. We're just coming together as a team right now."
As for the lanky lefty himself?
"It felt really good to be healthy," Paxton said. "I was just thankful to not feel any soreness or pain in the arm out there doing what I did. So that's great news."