Hernandez said he felt fine on Wednesday and will throw a bullpen session on Thursday. In the past, Hernandez rarely threw off the mound in the bullpen between starts, but he is expected to do more of that this season.
"He's in a pretty good rhythm right now, he feels good about his delivery and he wants to stay with that," Servais said. "So I would expect him to do a little more of that."
The Mariners are already without starter Drew Smyly, who was placed on the 60-day disabled list Tuesday after being diagnosed last week with a strained flexor in his left elbow, so keeping Hernandez healthy early is important for a team hoping to get off to a good start in the American League West race.
Hernandez received treatment from the Mariners' medical staff on Tuesday afternoon and was walking with a bounce in his step by the time he emerged from the training room.
Hernandez gave up two runs on five hits -- including two solo homers -- in five innings in Seattle's 3-0 Opening Day loss. He struck out six and didn't walk a batter in a 65-pitch performance.
But the six-time All-Star came up limping after breaking late to the bag to take a throw at first on a fourth-inning groundout and was replaced before the sixth inning despite getting the next four batters out without issue.
"I thought he threw the ball fine," Servais said. "I didn't think it affected him on the mound at all. It certainly affected him getting off the mound and that's where the concern lies."
Hernandez spent seven weeks on the disabled list last year with a strained calf, the first time he'd been on the DL since 2008, and he finished the year 11-8 with 3.82 ERA in 25 starts. His 153 1/3 innings ended a streak of eight straight seasons with 200-plus frames and 10 years with 190 or more.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.