Update (6:40 PM ET): Nick Piecoro reports that the Tigers will receive prospects Dawel Lugo, Sergio Alcantara, and Jose King from the Diamondbacks.
Lugo, 22, was originally signed by the Blue Jays out of the Dominican Republic for a $1.3 million signing bonus. The Jays sent him to the D-Backs in August 2015 for infielder Cliff Pennington. This season, with Double-A Jackson, Lugo hit .282/.325/.428 with seven home runs and 43 RBI in 369 plate appearances. He has mostly played third base this year but has also played some shortstop.
Alcantara, 21, was signed by the Diamondbacks in July 2012. He has had stops at various levels of Single-A over the last five years. This season, with High-A Visalia, Alcantara hit .279/.344/.362 with three home runs, 28 RBI, and 11 stolen bases in 378 PA. He has spent the overwhelming majority of his minor league career playing shortstop, but has logged some time at second base.
King, 18, was signed by the Diamondbacks in October 2015. This season, in rookie ball, he hit .261/.333/.348. He has spent nearly equal amounts of time playing second base and shortstop.
Lugo was the Diamondbacks’ No. 4 overall prospect according to MLB Pipeline. Alcantara was No. 15 and King did not make the top-30.
Martinez, 29, is hitting .305/.388/.630 with 16 home runs and 39 RBI in 232 plate appearances this season. He missed the first five weeks of the season with a Lisfranc sprain in his right foot. Martinez will become a free agent after the season, so this is strictly a rental for the Diamondbacks.
The 53-39 Diamondbacks are 10.5 games behind the Dodgers in the NL West, but currently lead the Rockies by a half-game for the first of two Wild Card slots. Adding Martinez gives them a big bat to help in the final two and a half months of the season.