SAN DIEGO -- The Padres' wide-open third-base race took an unexpected turn on Tuesday.
Christian Villanueva, the 27-year-old infielder who burst onto the scene with 20 homers and a .750 OPS in 2018, was designated for assignment, as part of a series of moves on Tuesday as the Padres cleared space on their 40-man roster. In an Instagram post, Villanueva confirmed he's headed to Japan to play for the Yomiuri Giants, who bought his contract rights from San Diego.
It's a surprising twist, given that Villanueva figured to be in the mix for a starting job at the hot corner next season. Evidently, the Japanese club approached the Padres with the possibility of working out a deal to acquire Villanueva, who had pushed for the opportunity.
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The Padres negotiated with Yomiuri on a fee that would release his contract. Villanueva, meanwhile, negotiated his own contract separately with the club. Eventually all parties came to an agreement.
Padres general manager A.J. Preller refused to comment on the specifics of the move when reached Tuesday evening.
"In talking to [Villanueva's] camp, they felt like there was a real opportunity for him in some different things that we felt we'd give him the chance to explore and we'd be supportive of, understanding that we were going to have to look at some other different options at third base," said Preller.
In his rookie season, Villanueva batted .236/.299/.450. He broke out with a brilliant April that earned him National League Rookie of the Month honors before regressing during the remainder of the season.

Villanueva was among a handful of candidates to open the 2019 season at third base for San Diego, all of whom have flaws. With Villanueva gone, it's now a near certainty the Padres look to add in their infield. As things stand, William Myers is probably the projected Opening Day third baseman, and he struggled mightily in his debut at the position in August and September.
"We're still looking at different fits, different options, going forward," Preller said. "On the roster, you have Wil, who we'll still keep looking at. … We'll probably get through the Winter Meetings and have a clearer picture with where we're at third base, and more specifically with Wil."
Myers is an obvious candidate to be traded, and MLB Network Insider Ken Rosenthal reported Tuesday that the Padres have spoken with the Mariners about a potential deal. It's also very possible that the Padres move Franmil Reyes or Hunter Renfroe, which would presumably clear space to allow Myers to shift back to a corner-outfield spot.
In any case, it seems unlikely that all three are in San Diego on Opening Day, meaning third base is probably vacant. Ty France was one of seven prospects added to the 40-man roster on Tuesday, and he'll compete for the job in Spring Training, as will Jason Vosler, who was acquired in a trade with the Cubs. The duo combined to hit 45 home runs in the upper levels of the Minor Leagues last season.
Still, it's far likelier the Padres add a third baseman via trade or free agency over the next month. They were almost certainly going to do so, even before Villanueva's departure. Now, it's a necessity.