The Seattle Mariners have added another arm to their pitching depth, claiming right-handed pitcher Nolan Kingham off waivers from the Texas Rangers. The move gives Seattle another experienced option to develop at the minor league level while providing the organization with additional insurance for its pitching staff.
The Rangers had recently designated Kingham for assignment, creating an opportunity for the Mariners to acquire him without giving up a player or prospect in return. Seattle had several open spots on its 40-man roster, meaning the club was able to make the waiver claim without needing to remove another player.
Rather than immediately placing Kingham on the major league roster, the Mariners have assigned him to Triple-A Tacoma. That gives him an opportunity to continue working on his game and potentially put himself in position for another opportunity in the majors later in the season.
Kingham’s path to Seattle is an interesting one. The 29-year-old right-hander did not arrive in the major leagues through a straightforward progression through the minor leagues. In fact, only recently, he was pitching professionally in Mexico after his time in the Atlanta Braves organization came to an end.
Atlanta selected Kingham in the 2018 MLB Draft, but the organization released him in March 2024. With his options changing, Kingham continued his career in the Mexican League, joining the Sultanes de Monterrey. He remained with the club into the beginning of the 2026 campaign.
His performance early this season helped him attract attention from the Rangers. Kingham opened the year with six starts for Monterrey and produced an impressive 1.82 ERA. That strong stretch was enough to convince Texas to sign him to a minor league contract and give him another chance to work his way toward the major leagues.
After joining the Rangers organization, Kingham reported to Triple-A Round Rock. His numbers there were considerably less impressive from an ERA standpoint. Across 11 appearances, he worked 46 1/3 innings and posted a 6.99 ERA.
At first glance, that figure could make the move seem like a surprising one for Seattle. However, there are factors that provide additional context to his performance. Round Rock plays in the Pacific Coast League, a notoriously hitter-friendly environment, and Kingham’s underlying numbers were not nearly as alarming as his ERA might suggest.
His strikeout rate was 21.5 percent, while his walk rate came in at 8.3 percent. He also recorded a 41.7 percent ground-ball rate. Those numbers are not overwhelming, but they indicate a pitcher who was capable of producing reasonably competitive results in several important areas.
Some of the damage reflected in Kingham’s ERA also appears to have been influenced by unfavorable results on balls put into play. His batting average on balls in play was .344, while he stranded only 62.3 percent of opposing baserunners. Those figures suggest that his ERA may have been somewhat inflated by circumstances beyond his direct control.
Texas eventually rewarded Kingham with his first major league promotion at the beginning of August. Unfortunately for him, the opportunity was brief. He appeared in just one game for the Rangers, pitching one inning and allowing one earned run before eventually being designated for assignment.
Now, Kingham gets another chance with Seattle.
For the Mariners, the transaction carries very little downside. Seattle had open space on its 40-man roster, so the organization did not have to make a difficult roster decision simply to bring him aboard. The club can now evaluate Kingham in Tacoma and determine whether his skill set could become useful at some point.
The timing also makes sense because Seattle recently altered its rotation by trading veteran right-hander Luis Castillo. Although the Mariners still possess considerable starting-pitching depth, adding another arm gives them greater flexibility as the season progresses.
Seattle continues to have an impressive group of established starters. Logan Gilbert, George Kirby, Bryan Woo, Bryce Miller and Emerson Hancock give the Mariners a formidable starting five. With that group available, Kingham is unlikely to immediately be asked to take on a major role.
However, baseball seasons rarely go exactly according to plan. Injuries, workload management, doubleheaders and unexpected struggles can quickly create openings in a pitching staff. That is where having an optionable pitcher like Kingham can become valuable.
The Mariners also have highly regarded young pitching options waiting behind their established rotation. Kade Anderson and Ryan Sloan are among the prospects who could eventually factor into the organization’s plans. That makes Kingham’s role even more likely to center around depth rather than an immediate push into the rotation.
Still, Seattle could benefit from having a pitcher capable of handling multiple innings. Kingham could potentially become an option for a spot start, long-relief assignment or emergency rotation role if the need arises.
The Mariners recently lost another potential depth option when Casey Lawrence opted out of his minor league contract. That development makes Kingham’s addition more useful, particularly if Seattle wants to maintain enough experienced pitching depth at Triple-A.
One of the most attractive aspects of the move is Kingham’s roster flexibility. He has a full complement of minor league options, allowing Seattle to keep him at Tacoma without being forced to make an immediate decision about his major league future.
That flexibility could be particularly important later in the season. If Kingham performs well in Tacoma, the Mariners can bring him up when circumstances require it. If the team does not need him immediately, he can continue pitching in Triple-A and remain available as an organizational insurance policy.
For Kingham, meanwhile, the waiver claim represents another opportunity to continue a remarkable comeback attempt. Just a couple of years ago, his professional career appeared to be moving in a different direction after his release from Atlanta. His decision to continue pitching in Mexico helped him rebuild his career, and his strong start to 2026 eventually earned him another chance with an MLB organization.
Although his first major league appearance did not produce spectacular results, one inning is far too small a sample size to determine what he can ultimately accomplish at the highest level.
Seattle is therefore taking a low-risk approach. The Mariners are not counting on Kingham to immediately solve a major pitching problem. Instead, they are adding another arm to their depth chart and giving him an opportunity to prove that he can contribute.
If he can rediscover the form that produced his impressive 1.82 ERA in Mexico, Kingham could eventually become a useful piece for the Mariners. Even if he never becomes a permanent member of Seattle’s major league staff, having a pitcher with experience, flexibility and starting potential available in Triple-A could prove valuable over the final stretch of the season.
The waiver claim may not be the kind of move that dominates headlines, but it fits the Mariners’ broader need for pitching depth. With Castillo no longer in the rotation and the long MLB season still demanding plenty from every pitching staff, Seattle is ensuring it has additional options available.
For now, Kingham will head to Tacoma and work to earn his next opportunity. Whether that chance comes as a starter, long reliever or emergency call-up remains to be seen. But after making his way back from the Mexican League and reaching the majors for the first time, he now has another organization willing to give him a shot.
