SAN FRANCISCO -- The D-backs designated catcher John Ryan Murphy for assignment, clearing the way for Saturday’s starting pitcher Taylor Clarke to be added to the roster, but the bigger takeaway from the move is that Carson Kelly will get more playing time behind the plate.

Murphy was part of a three-catcher rotation with Kelly and Alex Avila. While the D-backs favored having three catchers, they will now go with two and also have Blake Swihart, who has caught in the past, as an option late in games.

“Those are very hard decisions for us to make,” D-backs manager Torey Lovullo said. “[Murphy] is a part of the fabric of a lot of our success here for the past year and a half.”

When a player's contract is designated for assignment -- often abbreviated "DFA" -- that player is immediately removed from his club's 40-man roster, and 25-man roster if he was on that as well. Within seven days of the transaction (it was previously 10 days), the player must either be traded, released or placed on irrevocable outright waivers.

Murphy caught all 11 of Zack Greinke’s starts this year and Lovullo said he has not decided yet whether Kelly or Avila will catch Greinke going forward.

Murphy led baseball this year in pitch framing, converting 54.5 percent of non-swing pitches into called strikes in the Shadow Zone.

Kelly ranks fifth among qualified catchers in the metric with a 53.5 percent mark.

And it's Kelly’s development at running a game and in swinging the bat that left the D-backs looking for ways to get him more playing time.

“I think that’s a strong part of this equation,” Lovullo said. “More recently, we’ve been more and more impressed with his ability to control the game from behind the plate, control the at-bats. Some of the things he does are already off the charts, such as blocking and throwing. The other parts of the game he has to grow and learn. He’s been doing that. We’ve been centering our conversations with how he’s been growing and developing day by day.”

Over his last 13 games entering Saturday, eight of which he started, Kelly has a slash line of .355/.500/.774.

Left field playing time

With David Peralta on the 10-day injured list with inflammation in the AC joint of his right shoulder, Tim Locastro and Swihart will share time in left field.

“I’m super excited about their opportunity,” Lovullo said. “We’re going to miss David, but it’s going to give two guys a chance to go out there and perform.”