TAMPA -- The Rays added left-handers Ian Seymour and Joe Rock to their 40-man roster on Monday, protecting two of their top pitching prospects from the upcoming Rule 5 Draft.

Seymour is the Rays’ No. 17 prospect and Rock is No. 22, according to MLB Pipeline. Both pitched for Triple-A Durham this past season, putting them in position to contribute for the Rays as soon as next season.

• Which prospects are getting roster spots?

To clear a spot on their 40-man roster, the Rays designated for assignment infielder Austin Shenton. The club also announced it agreed to a Major League contract for 2025 with right-hander Cole Sulser, who was eligible for salary arbitration. Sulser’s split contract is worth $900,000 in the Majors and a guaranteed $450,000 in the Minors.

The deadline for teams to protect eligible players from the Rule 5 Draft is Tuesday at 6 p.m. ET. The Rays took care of their business a day early by selecting the only two eligible prospects on MLB Pipeline’s Top 30 list. The Rule 5 Draft will take place on Dec. 11 during the MLB Winter Meetings in Dallas.

Seymour, 25, was named the Rays’ Minor League Pitcher of the Year after posting a 2.35 ERA and a 0.95 WHIP with 162 strikeouts in 145 1/3 innings over 27 starts for Double-A Montgomery and Durham.

Seymour led Rays Minor Leaguers in ERA, innings, strikeouts and WHIP, and his ERA was the 10th-lowest among all full-season Minor League pitchers. Seymour’s five-pitch arsenal is headlined by a low-90s fastball and a plus changeup that helped him hold opponents to a .187 average while walking only 7.1% of the batters he faced.

• Here are the best recent Rule 5 Draft picks

A second-round pick by the Rays out of Virginia Tech in the 2020 MLB Draft, Seymour didn’t make his professional debut until July 2021 due to flexor soreness. He dominated the rest of that season, recording a 1.95 ERA with 87 strikeouts in 55 1/3 innings over 14 outings. His ascent was stalled in 2022, when he underwent Tommy John surgery, but he returned to the mound in ’23 and returned to form this year.

“Ian had a really, really fine season. I think No. 1 is the amount of innings he was able to post this year coming off of injury,” assistant general manager Kevin Ibach said in September. “You never know how that's going to work out, if a guy's going to have a setback because of previous injuries. But I think we saw a little bit of a glimpse of what we saw with Ian prior to the injury -- and then some.

“The fastball-changeup combo is what is really notable about him. … In games that he doesn't even have his best stuff, self-admittedly, he'll go out there and be able to find a way to get you through six or seven innings and get people out.”

The Rays acquired Rock, 24, from the Rockies last March, trading away 2019 first-round pick Greg Jones. The 6-foot-6 Rock, who throws three pitches with a funky delivery, posted a 4.58 ERA and a 1.40 WHIP with 132 strikeouts in 139 2/3 innings over 27 outings (23 starts) for Durham. Rock finished the season with his best start, striking out 10 while allowing only four hits and a walk over seven scoreless innings against Memphis.

Shenton, 26, cracked the Rays’ Opening Day roster due to a series of Spring Training injuries to key left-handed hitters but played sparingly. The left-handed-hitting corner infielder had a slash line of .214/.340/.405 with a home run in 50 plate appearances over 19 games. But he has thrived in Triple-A, slashing .276/.391/.541 in 144 games at that level from 2023-24.

Sulser made his Major League debut for the Rays in September 2019 and made his way back in a late-July deal with the Mets. The 34-year-old pitched 11 2/3 scoreless innings in six appearances for Tampa Bay, striking out eight and walking six. He posted a 1.66 ERA over 33 appearances in Triple-A this past season.