The New York Mets are heading toward selling at the trade deadline and their failure to fill first base is a big reason why. The arguments about letting Pete Alonso go in the offseason have raged on, particularly with the Orioles' first baseman off to a strong year in Baltimore, but two things can be true in regards to the Polar Bear.The 2026 Mets would undoubtedly be a stronger team if they had Alonso on it, particularly given Jorge Polanco's injury-related absence creating big issues at first. Alonso can only do so much, however, as the Orioles are eight games under .500 with him and the Mets would probably be in a similar position due to a variety of other issues that emerged in their doomed April.The struggles on the right side of the infield have been a big issue for the Mets this year in terms of lineup and roster construction. While second base is a separate issue due to Marcus Semien being under contract for two more seasons after this one, first base is a bigger issue since there aren't any easy answers.What are the Mets' internal options at first base?The initial plan at first base was Polanco, which was questionable from the jump due to his lack of big league playing time at first base. The Mets also kept the duo of Brett Baty and Mark Vientos around to give themselves options there, with Jared Young making the team out of camp and offering early contributions before getting hurt.Young's knee injury and other infield injuries shifted Baty over to third base, meaning Vientos was the unquestioned first baseman for a while. That experiment went quite poorly, with Vientos performing as one of the worst position players in the league, but Young's return has provided a lift there.The Mets have essentially made Young the primary first baseman since his return, with interim manager Andy Green promising he would see most of the at-bats there, but his struggles against lefties make a platoon ideal there. Vientos is on thin ice now with Eric Wagaman receiving a start at first on Sunday while the recently signed Christopher Morel, who was once a rumored part of a Pete Alonso trade package from Chicago, has a similar profile and could supplant Vientos if he hits at Triple-A Syracuse.There is also the case of Polanco, whose Achilles issues have made it nearly impossible to assume he can play first this season. Polanco may be limited to DH duty for the remainder of this year and it may be wise for the Mets to just assume he will be in that spot for the remainder of his contract.Do the Mets have any promising prospects at first base?The Mets do have one prospect to watch at first in Ryan Clifford, one of the key returns in the Justin Verlander trade in the summer of 2023. Clifford offers the kind of pop the Mets need after losing Alonso, slugging 14 home runs and driving in 40 runs in 282 at-bats for Triple-A Syracuse, but his .191 batting average is alarming.The big issue for Clifford is strikeouts as he has punched out a whopping 117 times already, good for an unsustainable 36.9% clip. Unless Clifford can adjust to breaking balls and cut down on his strikeout rate he isn't a viable big league option even if the Mets sell off pieces.There are intriguing names in the lower levels of the minors who could help eventually, such as recent trade acquisition Cole Mathis, utility type Chris Suero and A-ball prospect Randy Guzman. None of them, however, have the type of profile that screams "can't-miss prospect" like Carson Benge or A.J. Ewing did.Could the Mets trade for a first baseman?There aren't many first basemen projected to be available at the deadline. Christian Walker and Willson Contreras, both of whom have been linked to the Mets in the past, may have been available a month ago but the recent surges from Houston and Boston respectively could inspire those teams to buy instead.It is possible that David Stearns, who recently received strong backing from Steve Cohen, could look to acquire a first baseman under club control beyond this season. One potential fit could be Royals' first baseman Vinnie Pasquantino, who has two years of club control remaining and is in the midst of a down year.Trading for Pasquantino, or any sort of player with club control, is an expensive proposition. The Mets may try to take advantage of buying lower on a player like Pasquantino, but the Royals also can ask for a lot since they are trying to win in Bobby Witt Jr.'s prime and Pasquantino has proven he can help in that regard.What are the first base options?The short answer is not great. Assuming Yandy Diaz stays in Tampa Bay, the top free agents at first base entering the 2027 offseason are players past their prime who would be looking for one-year deals (Paul Goldschmidt, Carlos Santana, Josh Bell if his team option is declined) or players without extensive track records of success.The most intriguing free-agent fits would be Ryan Mountcastle or Andrew Vaughn, who has resurrected his career in Milwaukee. Both could help as complementary pieces, but they would be more short-term fixes in the mold of what Polanco was intended to be.What is the best course of action for the Mets at first?The smart play would be to call the Royals and see what they can do to acquire Pasquantino. If Kansas City is open to moving him, it would be a great fit to fill the first base hole on a long-term basis.The short-term answer is probably Young in a platoon with someone like Morel until they can reassess in the offseason. Polanco can't be counted on here, but the options at first are a bit tricky unless a deal is coming by August 3.Add us as a preferred source on GoogleFollow