It's the result of the World Baseball Classic and his determination to prove last year's struggles were an anomaly.
"I've got to prove people wrong," Hernandez said after taking his physical with the Mariners. "I feel fine. I'm healthy. That's the main thing."
How Hernandez approached the offseason was one of Seattle's big questions after watching its ace have a rocky 2016 season that included a lengthy stint on the disabled list due to a leg injury. Hernandez was 11-8 with a 3.82 ERA in 25 starts last season. It was the fewest starts in a full season in his career and his ERA was its highest since 2007. He walked more batters, struck out fewer and was prone to giving up the long ball.
It was unlike the Hernandez most have come to expect, which made how he would respond one of the big topics that could ultimately determine how good Seattle is in 2017.
"The offseason has been good to me," Hernandez said.
Hernandez spent most of his time in Miami working out with the same trainer, "Iron Glenn," who has worked out teammates Nelson Cruz and Robinson Cano in previous seasons. Hernandez reported at 224 pounds, which is up from last season when he reported at 207, but he believes the increased weight comes via strength that will help him last the season.
"Working on everything. The whole body, to be balanced, left and right side," Hernandez said. "[We] do a lot of bands. We do a lot of stuff."
Hernandez also had a brief two-game stint in the Venezuelan Winter League to start getting ready for the World Baseball Classic.
Hernandez said he still needed to finalize his pitching schedule with the Mariners' staff but is likely to throw in two spring training games before joining Venezuela. Hernandez expects to pitch the pool-play opener for his country on March 10 against Puerto Rico. Hernandez did not pitch for Venezuela during the 2013 WBC.
"It means a lot. I think we've got a pretty good team to win the whole thing," he said.
Hernandez will also spend the early days of spring training figuring out Seattle's overhauled roster. There are just eight players remaining on the 40-man roster from when general manager Jerry Dipoto took over in September 2015.
"There's a lot of new faces. I have to sit down and see who the guys [are]," Hernandez said. "But we look different. More athletic."