As Memorial Day approaches, the MLB trade rumor season begins to take shape, providing insights into potential transactions ahead of the July 31 deadline. Moneyline presents a BS Meter to gauge the credibility of these rumors, categorizing them as non-existent, low, medium, or high. This tool is designed to assist fans in determining how much weight to assign to various reports without questioning the reliability of the sources.

One rumor gaining traction comes from MLB.com's Mark Feinsand, who reported that the Philadelphia Phillies reached out to veteran reliever David Robertson prior to the public announcement of José Alvarado’s 80-game suspension for a performance-enhancing drug violation. Feinsand noted that while contact was made, there were 'no serious talks' regarding a potential deal. This assessment earns a 'low' rating on the BS Meter, as the legitimacy of the contact is plausible. The Phillies are likely in need of bullpen reinforcement, especially after losing Alvarado, and Robertson could serve as a valuable addition. However, his prolonged status as a free agent raises questions about potential obstacles to a deal.

Another notable rumor involves the Los Angeles Dodgers and Chicago Cubs keeping a close eye on third baseman Ryan McMahon of the Colorado Rockies, as reported by Bob Nightengale of USA Today. This speculation carries a 'high' designation on the BS Meter due to the uncertainty surrounding the Rockies' willingness to sell, particularly given their underwhelming performance this season. McMahon has struggled at the plate with a .211 batting average and a .706 OPS, while maintaining a solid defensive reputation. However, his $32 million salary between 2026 and 2027 presents a potential hurdle for interested teams. It remains to be seen whether the Rockies will pursue a trade, especially considering the Dodgers might only act if they deem Max Muncy's struggles warrant concern.

In contrast, Jon Heyman discusses the unlikely scenario of the Pittsburgh Pirates trading their young prospect Paul Skenes, stating that there is 'no way, no how, no chance.' This claim earns a 'non-existent' rating on the BS Meter. Despite the Pirates' challenging season, Skenes, at just 22 years of age, represents a core piece for future success, especially with his impressive 2.12 ERA in his first 33 MLB starts. Trading a talent of this caliber at such an early stage would be illogical for the Pirates, making this rumor highly implausible.

Additionally, Nightengale suggests that Rhys Hoskins could be a fitting target for the Boston Red Sox if the Milwaukee Brewers decide to part with him. While this is an opinion rather than a hard report, it garners a 'low' rating due to its logical assessment of Hoskins' power potential. However, the Brewers, sitting at 24-26, are still within contention, notably trailing the Chicago Cubs. Hoskins' strong resurgence with a .902 OPS following an ACL injury could prompt the Brewers to seek a trade, particularly if they can manage a financial aspect of the deal.

Lastly, there's speculation about Luis Robert Jr.'s trade prospects. Heyman remarked that unless Robert significantly improves his performance, he is unlikely to garner strong interest in the trade market. Again, this statement earns a 'non-existent' mark on the BS Meter. Robert had previously shown promise with a contract viewed as team-friendly, but his recent stats reflect a sharp decline to a .210 batting average. Teams may perceive him as a rental player, lessening his trade value in discussions.