PHILADELPHIA -- The D-backs adjusted their 26-man roster for the National League Championship Series against the Phillies, adding rookie right-hander Slade Cecconi and leaving off infielder Jace Peterson.

Arizona had gone with 12 pitchers and 14 position players for the NL Division Series against Los Angeles because, with a number of off-days, it did not need to use more than three starting pitchers.

However, the D-backs will need four starters for a best-of-seven NLCS, and Cecconi provides them with some length in the bullpen or another option to start.

The 24-year-old Cecconi started 23 games this season for Triple-A Reno, where he had a 6.11 ERA. He posted a 4.33 ERA over seven appearances, including four as a traditional starter and one as the bulk pitcher following an opener, with the D-backs this year.

“I think this series is a little bit different,” D-backs manager Torey Lovullo said. “We're going to play potentially seven games in nine days. We just felt like to give us a little bit of coverage in any type of situation, we need a little bit of length coming out of the bullpen.”

Peterson was acquired from the A's at the Trade Deadline and slashed .183/.276/.258 over 106 plate appearances. He was a last-minute addition to the NL Wild Card Series roster after outfielder Jake McCarthy was injured, but he did not play. Peterson was on the NLDS roster, going 0-for-1.

Here is the D-backs’ full roster:

Catchers (2): Gabriel Moreno and Jose Herrera

Infielders (7): Christian Walker, Ketel Marte, Geraldo Perdomo, Emmanuel Rivera, Jordan Lawlar, Evan Longoria and Pavin Smith

Outfielders (4): Corbin Carroll, Alek Thomas, Tommy Pham and Lourdes Gurriel Jr.

Pitchers (13): Slade Cecconi, Zac Gallen, Merrill Kelly, Brandon Pfaadt, Ryne Nelson, Paul Sewald, Kevin Ginkel, Andrew Saalfrank, Ryan Thompson, Kyle Nelson, Miguel Castro, Joe Mantiply and Luis Frías