SEATTLE -- Without question, 2018 seemed like a tale of two seasons for James Paxton . And it's no coincidence that Paxton's early success and second-half struggles closely mirrored those of his Mariners.

Remember the dominant 16-strikeout game by the big Canadian and the subsequent no-hitter in Toronto in May? Those were the days, the glory days, for a Seattle squad that seemingly had everything going its way in the first three months of the season.

Paxton pitched only every fifth game, so the downturn of fortunes wasn't all on the lanky lefty from Ladner, B.C. Indeed, second-half slumps by some of his teammates were more troublesome. Felix Hernandez went 0-8 in the final three months. Kyle Seager batted .200 after the All-Star break and Seager, Dee Gordon, Mike Zunino and Ryon Healy all had on-base percentages under .300 in that span.

But Paxton's rise and fall seemed especially symptomatic of Seattle's season, given his extreme first-half success, followed by the disappointing finish.

On July 1, when Paxton overpowered the Royals for eight scoreless innings at Safeco Field with just two hits and 11 punchouts, his record stood at 8-2 with a 3.39 ERA in 18 starts and the Mariners were rolling at 54-31.

Shortly thereafter, the wheels started wobbling for both the Mariners and their new No. 1 starter. Due to a back issue, a line drive off his pitching arm and then a bout with pneumonia, Paxton wound up making just 10 more starts in the final three months, going 3-4 with a 4.62 ERA while Seattle struggled with a 35-42 record.

Looking back, Paxton acknowledges the back issue that arose in his final start before the All-Star break wound up knocking him off kilter for some time as he tried to compensate for the lingering problem upon his return.

"I never really got quite back to myself after that," Paxton said. "When you get hurt and start trying to compensate and get in a position that doesn't hurt, throwing-wise, then things kind of get lost and you have to work back to what works for you.

"For me, I got close, then I got hit in the elbow, and then I got closer and got sick. It's frustrating, but I know what I have to do moving forward, and I'm looking forward to putting in the work to get myself ready."

That's the burning desire Paxton takes with him into the offseason again. His primary goal last winter was to eliminate any possible physical issues through a regimented diet and workout program. He did wind up throwing a career-best 160 1/3 innings with 208 strikeouts, again leaving no doubt about the upside potential.

"There were some great highlights this year," Paxton said. "I went through some stretches where I threw the ball extremely well. I learned a lot about myself and about pitching. I learned some stuff about my body, going through the back stuff this year, things I can improve upon."

Paxton knows his injury history hangs like a shadow over his career, seemingly the one thing standing in the way of greatness. It's been an odd assortment of ailments that included a strained lat muscle in 2014, a torn tendon in his middle finger in '15, a bruised elbow after getting hit by a line drive in '16, a strained forearm and strained pectoral muscle in '17 and now the back problem, another line drive injury and the late-season illness.

None of those issues have involved his shoulder or elbow, injuries that typically derail pitchers, and he's done everything the Mariners training staff and doctors have suggested could eliminate any recurrences.

"With every injury I've had in my career, knock on wood, I've been able to remedy it and figure out what I need to do to make it not happen again," Paxton said. "Hopefully I'm running out of things I need to remedy, and I can get some smooth sailing here."

Paxton will take a short break this offseason, then commit again to a winter filled with work aimed toward achieving that elusive full season. He saw what was possible in the first half of 2018, both for himself and his team, and he is eager to take it to the finish line next year.

"We really showed ourselves what we're capable of and then in the second half, things kind of fell apart on us," Paxton said. "Even still, we won 89 games, which we hadn't done since I've been here. It just happens we have some really good teams in our division.

"It was one of those years where the A's surged. What they did was absolutely incredible. And the Astros are the Astros. They have four aces and a lot of depth. Still, we won the season series against both those teams. We can beat those guys. We just lost some games this year we shouldn't have lost against lesser teams.

"We shot ourselves in the foot a few times. All we can do is learn from those losses and continue to work to have a consistent season, throughout the entire season so we can break through and get to that postseason we all want so badly."