3:07pm: It’s a “significant” lat strain for Reyes, GM Mike Girsch tells reporters (Twitter link via Mark Saxon of The Athletic). There won’t be an exact timetable on his recovery until he receives a second opinion, per Saxon, though certainly that update from Girsch is far from promising. An MRI taken this morning revealed the injury, tweets Derrick Goold of the St. Louis Post-Dispatch.

2:09pm: The Cardinals announced today that they’ve placed top prospect Alex Reyes back on the disabled list with a strained right lat muscle. St. Louis also optioned struggling outfielder Tyler O’Neill and right-hander John Gant to Triple-A Memphis. Filling those spots on the roster will be lefty Austin Gomber, righty Mike Mayers and first baseman Luke Voit, each of whom has been recalled from Memphis.

Reyes had Cardinals fans salivating as he tore through minor league batters in a rehab assignment, and he looked dominant in the first inning of yesterday’s return affair before slowly experiencing a dip in his velocity over the subsequent three innings. President of baseball ops John Mozeliak told The Athletic’s Jim Bowden last night that Reyes’ elbow was “fine,” and that appears to be the case, though the lat muscle presents a new issue for the vaunted young right-hander to overcome. While any injury to Reyes’ throwing arm is of course a cause for concern for the organization, it’s likely a silver lining that the issue is not specific to his surgically repaired right elbow.

With Reyes back on the shelf, the Cards will once again deploy a rotation consisting of Miles Mikolas, Luke Weaver, Michael Wacha and Jack Flaherty as they await the return of ace Carlos Martinez from a lat strain of his own. Martinez did go out on a minor league rehab assignment today, per the team’s transactions page, but while he’s nearing a return, it seems that fans will have to wait for the a highly anticipated 1-2 punch of Martinez and Reyes atop the staff.

[Related: St. Louis Cardinals depth chart]

As for O’Neill, he’ll head back to Triple-A and look to make continued strides on his approach at the plate and his bat-to-ball skills. While the 22-year-old flashed the power that has made him such an intriguing prospect, early proclamations of a new star’s arrival were proven premature. O’Neill struggled enormously to make consistent contact, whiffing in 43.9 percent of his trips to the plate and in 13 of his final 19 plate appearances before being optioned out.

None of that is to suggest that O’Neill doesn’t have the potential to develop into a regular middle-of-the-order threat for the Cards, of course. While contact issues had plagued him earlier in his minor league tenure, he whittled his strikeout rate down to a more respectable 23.3 percent in Memphis this season before being called to the Majors. His approach still needs some refinement, though, as was evidenced by a 2.5 percent walk rate in Triple-A and a near-identical mark in his brief MLB tenure this season. O’Neill has mashed 13 homers in 120 PAs with Memphis and three in the bigs, though, so there’s little doubting the legitimacy of his power.

With O’Neill in the minors, it’ll be Marcell Ozuna, Tommy Pham, Dexter Fowler and Harrison Bader splitting up the bulk of the outfield duties. Meanwhile, in the rotation, it’s possible that Gomber could step up and make a spot start as the team awaits the return of Martinez. If not, he’ll give the ’pen a fresh lefty at a time when both Brett Cecil and Tyler Lyons have endured some considerable struggles. Gomber has made nine start in Memphis and logged a solid 3.60 ERA with a 63-to-17 K/BB ratio in 55 innings of work.

Mayers, meanwhile, will return for another stint to give the bullpen some depth. The 26-year-old has already been optioned to Memphis and incredible five times in the season’s first two months, and that seems likely to be the role he fills in St. Louis this season unless further injuries in the Majors carve out a more permanent spot for him.

The 27-year-old Voit is hitting just .243/.351/.348 in Triple-A so far in 2018, but he had a monster season there in 2017 and also hit .246/.306/.430 with four homers in 128 plate appearances at the Major League level. This’ll be his first appearance on the 2018 roster for the Cards.