Oakland A's injuries: Henderson Alvarez MRI 'inconclusive' & Mark Canha out for season

Oakland A's manager Bob Melvin says Henderson Alvarez's MRI returned "inconclusive", tweets A's beat writers (including the San Francisco Chronicle's Susan Slusser) from Bob Melvin's pre-game press conference. The MRI will be sent to Dr. James Andrews, who performed Alvarez's shoulder surgery in 2015, for a second opinion, tweets CSN California's Joe Stiglich. Alvarez did throw on Wednesday morning, however:

Henderson Alvarez (shoulder) doesn't want to talk to media today, but he told confidants he "felt OK" during today's throwing session.

— John Hickey (@JHickey3) May 18, 2016

Melvin says the fact nothing jumped out on Alvarez's MRI "does give you some optimism."

— Susan Slusser (@susanslusser) May 18, 2016

Before Tuesday's game, however, Oakland A's Dugout Show host Chris Townsend said he had heard that Henderson Alvarez's MRI returned "not good" and that Alvarez's velocity was way down last Sunday in what was supposed to be his final rehab start before joining the A's rotation this week.

Mark Canha out for season

On Tuesday, Mark Canha disclosed to A's beat writers (including the Bay Area News Group's John Hickey) that he has elected to undergo season-ending surgery for a hip impingement that has been bothering him all of this season. Canha, writes Hickey, "had hip and back problems dating to the final days of the 2015 season and he wasn't at all sure a cortisone shot would accomplish what he needed it to."

The good news is that there is no labrum damage. He only needs to have his femur shaved down because it is "somewhat misshapen." Sean Manaea and Eric Surkamp have also had the surgery and returned to action "with no new problems."

What the Canha news appears to mean is that Billy Butler moves from being the platoon DH against left-handed pitching to being the platoon first baseman against left-handed pitchers, at least until a better alternative is available. The A's have called up Max Muncy, but he is a left-handed batting corner infielder and outfielder who was was one of Triple-A Nashville's top hitters. Prospect Renato Nunez could eventually be called up if there are plate appearances available, but continued development is the priority for the 22-year-old.

The A's also now have an open spot on the 40-man roster, effectively, as they can transfer Canha to the 60-day disabled list when necessary.

Other injury news

Wondering why Jed Lowrie is on the DL with a shin contusion? He was in a walking boot for three days with this: pic.twitter.com/0kJUhu82cV

— Susan Slusser (@susanslusser) May 18, 2016

Lowrie is running again now and he thinks he might get one rehab game before coming off the DL when eligible May 25.

— Susan Slusser (@susanslusser) May 18, 2016

Lowrie will eventually play a couple minor league games before his return. He ran yesterday, said it went well but still swelling in shin.

— Joe Stiglich (@JoeStiglichCSN) May 18, 2016

Hendriks is still experiencing soreness when playing catch, so still not close to a rehab stint.

— Jane Lee (@JaneMLB) May 18, 2016

RHP R.J. Alvarez, coming off spring surgery, could throw off mound for #Athletics by end of week. He's been playing catch for about a week.

— John Hickey (@JHickey3) May 18, 2016