The Seattle Mariners touched base with the Chicago Cubs and Kansas City Royals in recent weeks regarding Starlin Castro and Billy Butler, reports Ken Rosenthal of FOX Sports. This news prompted Rosenthal to state it would still make sense for the Mariners to trade right-hander Felix Hernandez for the right package of players.

Rosenthal confirmed that, despite initial reports stating otherwise, the Cubs did not make Castro available. He also notes that Butler remains relatively untouchable as the Royals deem him to be a core piece.

While Rosenthal doesn’t believe a trade is on the horizon involving one of these players, he does believe the Mariners are in position to make a transaction happen if they want to.

Rosenthal knows the Mariners would love to lock up Hernandez long-term, though he expects the 2010 American League Cy Young winner to command a deal in the six-year, $155 million or seven-year, $180 million range. Rosenthal questions if this is the type of deal that would work out in the long haul for the Mariners.

Hernandez is earning $18.5 million this season, $19.5 million in 2013 and $20 million in 2014. Rosenthal admits not many teams would be willing to pay this price and surrender premium prospects.

Still, Rosenthal thinks a deal is achievable. As an example, he says the Mariners could send Hernandez and cash to the Royals in exchange for Butler and a top prospect such as Wil Myers or Jake Odorizzi.

While he doesn’t know if either team would accept this, Rosenthal doesn’t believe Hernandez should be considered untouchable.