As the calendar inches toward June and Memorial Day draws near, Major League Baseball (MLB) trade rumor season is set to gain momentum. With the trade deadline looming on July 31, various storylines are beginning to take shape, revealing potential trades and player movements. To help navigate these developments, Moneyline has introduced a "BS Meter" that categorizes rumors into four levels of credibility: non-existent, low, medium, and high. The objective is not to question the integrity of reporters or their insights but to provide fans with a clearer understanding of which rumors may hold weight in the lead-up to significant trades.

A notable rumor emerged from MLB.com's Mark Feinsand, who reported that the Philadelphia Phillies reached out to veteran pitcher David Robertson prior to the public revelation of José Alvarado’s 80-game suspension for performance-enhancing drugs. Feinsand remarked that no serious discussions occurred. The credibility of this claim is assessed as low; it is reasonable to believe that the Phillies, even before losing Alvarado, had been seeking reinforcement for their bullpen. Given that Robertson is still a free agent despite having had a solid season with the Texas Rangers last year, lingering questions arise regarding his current situation. At 40 years old, although he had a commendable 3.00 ERA in 68 games last season, uncertainty remains about whether he is awaiting the right opportunity or considering retirement. Even with a contract signed, it may take him time to return to MLB readiness, leaving the possibilities of his future with the Phillies or another franchise undetermined.

Bob Nightengale of USA Today mentioned that the Los Angeles Dodgers and Chicago Cubs are closely monitoring Ryan McMahon, as the Colorado Rockies may be open to trading him. The BS Meter rates this rumor as high due to the Rockies' past organizational behavior, which has typically leaned against being significant sellers mid-season. Despite a struggling season so far, the ownership and management's decision-making process will be critical in determining if they pivot this summer. McMahon, despite being a former All-Star, is having a challenging season with a batting average of .211 and an OPS of .706. While he excels defensively at third base, the considerable $32 million he will earn between 2026 and 2027 could deter teams, especially when considering his current performance. If the Rockies explore a trade, they may need to consider eating some salary or accepting a lesser prospect, which may influence their decision to retain a notable player on their roster.

In a different context, Jon Heyman has suggested there is virtually no likelihood of the Pittsburgh Pirates trading pitcher Paul Skenes this summer, asserting, "No way, no how, no chance." This assertion rates as non-existent on the BS Meter. Despite fans of competitive teams hoping for such a trade amid the Pirates’ disappointing season, it is important to note that Skenes, at just 22 years of age, is not arbitration eligible until 2027 and is unlikely to reach free agency before 2029. Given his exceptional start to his career with a 2.12 ERA in 33 MLB starts, trading a talent considered generational is highly improbable. The Pirates appear more focused on building their future around such players rather than exploring trade options.

Additionally, Nightengale expressed his belief that Rhys Hoskins could potentially be a perfect fit for the Boston Red Sox should the Milwaukee Brewers opt to part ways with him. The rumor rates low on the BS Meter since it represents Nightengale's opinion rather than a confirmed report. Hoskins, a left-handed power hitter, could thrive in Fenway Park’s hitter-friendly environment. However, the Brewers currently remain in contention at 24-26, making it uncertain if they will consider selling. The Brewers' previous decisions, such as trading Josh Hader despite being in contention, hint that they might prioritize the future over the present. Following a rough start to the season post-recovery from a torn ACL, Hoskins has shown resurgence with an OPS of .902, which could lead to him declining his $18 million mutual option for 2026 in favor of exploring free agency after a successful year. Trading Hoskins could yield valuable prospects while alleviating financial commitments.

Finally, Jon Heyman commented on the low likelihood of the Chicago White Sox trading outfielder Luis Robert Jr. if he continues to struggle, stating he would not fetch much in return if hitting under .200. This assessment is rated as non-existent on the BS Meter. Once a promising figure within the organization, Robert's recent statistics have raised concerns as he currently holds a batting average of just .210, which is a stark contrast to his past performance, including an impressive .264 average and 38 home runs last season. Additionally, Robert's history of injuries may weigh on teams' perspectives as they evaluate his trade value. Though he has displayed speed on the bases with 17 steals, the White Sox would likely see Robert as a rental candidate, with many fearing his may not be worth top prospects based on recent form and potential club option declines.