PEORIA, Ariz. — For much of last summer and all of the ensuing winter, the Padres pondered a concept: What if, before their rebuild reached completion, they spent unprecedented money to sign a first baseman who could hit, defend and lead a roster stacked with less-accomplished players?



Eric Hosmer on Tuesday shed his title as the most-discussed free agent of the offseason. The Padres’ new starting first baseman cut an imposing figure as he slipped into a jersey with “30” on the back, a tribute to the late Yordano Ventura. He posed for photos alongside Padres general manager A.J. Preller and owners Ron Fowler and Peter Seidler. Later, he stepped onto a nearby practice field with 66 new teammates as San Diego began its first full-squad workout of the spring.



The concept had turned into reality. Much, however, remained intangible.



“He’s just a great dude, and you can’t put your finger on one thing,” said Matt...