I suppose it was too much to hope the A's were just giving Marcus Semien a day off yesterday, and indeed he has hit the disabled list today with a wrist bruise that could turn out to be hiding a fracture. The latter would be bad, but would also help explain why the injury has been nagging for weeks on end. Contusions heal!

Chad Pinder comes up from Triple-A to replace Semien on the roster. I'm curious to see whether he or Adam Rosales gets most of the starts at shortstop in Semien's absence. I'd advocate for Pinder on a "let's see what he's got" basis; everyone knows what Adam Rosales is, and he's not likely to be a major part of the next good A's team. He'll get his occasional playing time either way. The open question is whether Pinder is the guy who hit .317/.361/.486 in Double-A in 2015 (which Clay Davenport translates to a .284/.323/.444 line in the big leagues that is beyond respectable for a middle infielder) or the one who hit .258/.310/.425 in Triple-A (.245/.293/.399 translation, which is maybe good enough to sit on the bench). If Semien's just got a bruise, then Pinder's not going to get much time against big-league pitching anyway, though every PA is one more PA for the A's coaches and scouts to get information from; but if Semien's got a fracture, then the team could give Pinder a few weeks to make an impression. We're still looking at a small sample in the scheme of things, but consistent playing time is consistent playing time.

Down at Triple-A, the Nashville infield has looked like this since the start of the season (second base, shortstop, third base):

• Pinder, Barreto, Chapman
• Barreto, Pinder, Chapman
• Pinder, Barreto, Nunez
• Pinder, Barreto, Nunez
• Pinder, Barreto, Nunez
• Pinder, Barreto, Nunez
• Barreto, Pinder, Nunez
• Barreto, Pinder, Nunez
• Pinder, Barreto, Nunez
• Nunez (!), Barreto, Olson (!)
• Mercedes, Barreto, Nunez

(Matt Chapman is out with a wrist injury of his own.)

That last bullet is tonight's starting lineup, with Melvin Mercedes being called up from Midland to replace Pinder. I'll forgive you if you're not familiar with Mercedes, who was a 16th-round pick in 2012 and who has posted a .255/.339/.324 line in the minors so far; he just reached Double-A this year, at 25, and obviously is getting his first exposure at Triple-A now as well.

Mercedes has played some shortstop in the past; one wonders whether the A's will have him do so at Nashville so that Barreto can keep getting reps at second base in anticipation of his eventual promotion to Oakland, where the most obvious available slot for him is the keystone, what with the subject of this post still manning shortstop competently.

EDIT: Susan Slusser quotes Bob Melvin that Rosales is going to be the regular shortstop. Lame.