SEATTLE -- Mariners starter Kendall Graveman landed on the 10-day injured list Tuesday with neck spasms, and the club also optioned right-handed reliever Zac Grotz to its alternate training site in Tacoma. Relievers Taylor Guilbeau and Joey Gerber were called up from the alternate training site to replace them on the 30-man roster.

Graveman was impacted by the neck issue during his start on Sunday. He said the problem first cropped up midway through his season debut in Houston on July 27. The 29-year-old right-hander is coming back from a two-year recovery following Tommy John surgery in 2018, and he threw extremely well in Spring Training and Summer Camp. However, he is 0-2 with an 8.31 ERA in his first two starts.

“He’s getting more tests done today,” manager Scott Servais said prior to Tuesday’s series opener against the Angels. “We’re waiting to get more results back now. He had a different scan done today and has talked to a number of different doctors, trying to figure out what the right treatment to go toward to try to clean this up and calm it down as quick as possible.”

The Mariners have gone with a six-man rotation to open the season and Servais indicated he’d like to stay with that plan, with lefty reliever Nick Margevicius – a former starter with the Padres – the likeliest candidate to take Graveman’s next scheduled turn Saturday against the Rockies.

“I do like the six-man rotation,” Servais said. “I think it’s been beneficial for those guys. Certainly with Marco [Gonzales], Yusei [Kikuchi] and Taijuan [Walker], allowing them to go a little bit deeper and also giving our young guys that extra day before they go out there again.”

Gerber, the club’s No. 19 prospect per MLB Pipeline, will be making his first appearance with the Major League club. The 23-year-old was an eighth-round Draft pick in 2018 out of the University of Illinois, and he is regarded as a promising young power arm in the system.

Gerber, a 6-foot-4 right-hander, was a Mid-Season All-Star with Class A Advanced Modesto last season, when he saved eight games and posted a 3.46 ERA with 39 strikeouts in 26 innings. He then put up a 1.59 ERA with 30 strikeouts in 22 2/3 innings over 19 outings after being promoted to Double-A Arkansas.

Gerber uses a rather violent, herky-jerky delivery, but has used a mid-90s fastball and effective slider combination to rise quickly through the lower levels of the Minors as a closing candidate.

“We like Joey a lot,” Servais said. “He does it differently. He’s a big-bodied guy who can throw really hard. He throws a ton of strikes, even though you watch his delivery and say, ‘How does he do it?’ He’s got a good feel for what he’s doing. It’s going to take hitters a little while to see and get comfortable against him. Hopefully with the ‘Wow’ factor he gets off to a good start.”

Guilbeau, who is ranked as the Mariners’ No. 23 prospect, rejoins the club for the second time this season. The 27-year-old lefty threw one inning, allowing one run on two hits and a walk, on July 27 at Houston after being recalled from the three-man traveling taxi squad during the opening road trip.

Guilbeau posted a 3.65 ERA in 12 1/3 innings over 17 appearances last year after being acquired from the Nationals at the Trade Deadline.

Grotz, 27, joins the group of extra players working out in Tacoma after putting up a 12.00 ERA in six innings over four appearances with the Mariners.

Get out the vote

Servais showed up for Tuesday’s online video call with reporters wearing a T-shirt encouraging people to register to vote, a timely reminder on primary election day. He’s worn similar shirts in the past and continues to encourage his players to register.

“It’s a way for everybody to have a voice,” he said. “I think we need to take it seriously. It is an opportunity to make change. I’d love to get all our players registered and have them vote as well. I think it’s very important, where we’re at right now.”

Servais said his discussions focus on the act of voting, not who to support.

“I’m learning a lot from our guys and asking questions and making sure they understand the importance of it,” he said. “Oftentimes the biggest change can happen locally at the state and local elections. We all know there’s a big one coming down the road here nationally. I just want to create awareness. Not to tell anybody how to vote, just make sure you have a voice and you use it.”