Headley's name and the Yanks have been linked in trade rumors for several years, particularly after Headley had an MVP-type season in 2012 and turned down a long-term offer from the Padres.
But after leading the National League in runs batted in and belting 31 homers in 2012, Headley has been injured and ordinary ever since. Though he has hit well in July, Headley takes a .229 average, seven home runs and 32 RBI to Yankee Stadium.
For his eight-year career as a Padre, Headley is a .266 hitter with 87 homers and 401 RBI in 908 career games.
In exchange, the Padres get infielder Yangervis Solarte and minor league pitcher Rafael de Paula. The Padres, who have had a hole at second base due to injuries, will have an immediate spot for Solarte, 27, a .254 hitter with six HRs and 31 RBI this season as a rookie for New York. He may take Headley's place at third, or fill in at second, allowing Jedd Gyorko to shift back to third when he returns from the disabled list (plantar fasciitis).
De Paula, 23, has gone 6-5 this year with a 4.15 earned run average with 104 strikeouts in 89 innings at Single-A Tampa. DePaula, from the Dominican Republic, led all Yankee minor leaguers in strikeouts in 2013 while being selected to the MLB Futures game. The hard-throwing right-hander is still trying to tame some wildness, reflected in 109 walks in 264 minor league innings.
The Yankees will also receive some cash to help cover Headley's $10 million salary.
Headley, 30, is arguably the best position player the Padres have developed since Tony Gwynn. The Padres' second-round selection in the 2005 draft out of the University of Tennessee, Headley progressed steadily through the system, making his Padres debut in 2007.
In 2011, Headley hit his career-best .289, but he missed six weeks in August and September due to injury and hit only four home runs. That started fans muttering.
The 2012 season started out much the same, but in June the team traded for White Sox slugger Carlos Quentin, whose addition to the lineup seemed to energize Headley. The promise all seemed to come together as Headley posted a record-setting second half, leading the NL with 115 RBI while batting .286 with 31 homers while being named NL Player of the Month for both August and September. He also was awarded a Gold Glove for his fine work at third base.
But Headley opened the 2013 season on the DL and never put things together, batting .250 with 13 homers and 50 RBI in 141 games. His similarly slow start this year on a notoriously bad-hitting club made it time for Headley to get a change of scenery.
He'll get that in New York, where the Yanks are involved in a tightening NL East race. The Padres, meanwhile, the worst-hitting team in baseball by nearly every measurement, are trying to hang onto third place with a record 12 games under .500.
The Padres open a series Tuesday against the Cubs in Chicago, while the Yankees continue to host the Texas Rangers.