Arizona Diamondbacks All-Star second baseman Ketel Marte has been placed on the 10-day injured list with an ankle injury. Marte has been battling the injury since August 10, after Garrett Stubbs sprained his leg.

The initial diagnosis on opening night was a contused right ankle. A few days later, Marte underwent an MRI and the diagnosis changed to a “mild ankle sprain.” The injury looked anything but minor, however, as Marte collapsed to the ground in pain while attempting to pitch as a pinch hitter in Sunday’s game.

A timetable for Marte’s return is unknown at the time of this writing, but medical staff remain confident that the original diagnosis is correct.

The corresponding move for Arizona was to bring back Pavin Smith from Triple-A Reno. Smith will cover at first base behind Josh Bell and will be a left-handed reliever.

Recently, Kevin Newman has been used as a defensive replacement at first base in the late innings, but he will play a lot of second base and shortstop in the next few days. Blaze Alexander was brought in from Reno last week to provide infield coverage.

While all of these supporting cast members have performed admirably at times throughout the season, Marte is irreplaceable. He is the heart and engine of the team. Marte’s batting average is .298 with 30 home runs, 81 RBIs and +12 defensive runs saved.

The Diamondbacks are also missing Gold Glove first baseman Christian Walker (oblique) and Gold Glove catcher Gabriel Moreno (left abductor muscle strain). They recently welcomed back starting pitchers Eduardo Rodriguez and Merrill Kelly, both of whom were out for four months with shoulder strains.

Although the Diamondbacks have held up well in the standings and hold the second wild-card spot with a 69-55 record, this latest setback threatens to be their worst yet. Josh Bell and Adrian Del Castillo have filled in admirably for Walker and Moreno, but no single player will be able to replace Marte’s performance.

Stay tuned to Arizona Diamondbacks On SI for more updates.