"As far as Baez versus Locastro, I think that ultimately Pedro has been a big part of what we've done all year. I trust him," Roberts said before Friday night's Game 1. "Arguably he's been our highest leveraged reliever outside of Kenley Jansen all year. So I just think it makes sense.
"I think the dynamic to flat out steal a base, I think that we don't have that guy. Can we steal a base, are there numerous guys that can steal a base? Absolutely. But that element of a sheer basestealer that Tim brought, we don't have that. So, but, you look at the Diamondbacks and a right-handed-dominant lineup. So to have Petey as a matchup guy with potential, I think that that gives us a big advantage too."
Baez, who made this year's roster despite going 0-4 with a 10.38 ERA in September, pitched in four of the five NLDS games last year against Washington and threw 3 2/3 hitless innings.
The Dodgers will carry 12 pitchers, three catchers, five infielders and five outfielders against Arizona. In last year's NLDS against Washington, the Dodgers carried 11 pitchers, and all of them pitched at least once.
The Dodgers also kept active outfielder Andre Ethier and rookie third catcher Kyle Farmer. Ethier made the roster primarily as a left-handed pinch-hitter after missing most of the regular season with a herniated disk. Last year, he made the postseason roster after missing most of the regular season with a broken leg.
Keeping Farmer allows the Dodgers to use Austin Barnes or Yasmani Grandal as a pinch-hitter and still have coverage behind the plate if something happens to the other catcher. Barnes is the club's best right-handed pinch-hitter.
"Also, I love Kyle's at-bat quality," Roberts said. "He can play third, he can play some second, some first. So he gives us that versatility. But his quality of at-bat played a factor in that."
Roberts said that reliever Ross Stripling, who also wobbled in September, made the club for reasons similar to Baez.
"As far as quality pitch making, he's as good as we have, really," Roberts said. "So to get the righty out, he gets lefties out. He gets length. So there is certainly an advantage having him on the roster."
New rosters will be submitted for the next two rounds if the Dodgers advance.
Pitchers (12): Pedro Baez, Clayton Kershaw, Tony Cingrani, Yu Darvish, Josh Fields, Rich Hill, Kenley Jansen, Kenta Maeda, Brandon Morrow, Ross Stripling, Tony Watson, Alex Wood.
Catchers (3): Austin Barnes, Kyle Farmer, Yasmani Grandal.
Infielders (5): Cody Bellinger, Logan Forsythe, Corey Seager, Justin Turner, Chase Utley.
Outfielders (5): Curtis Granderson, Enrique Hernandez, Andre Ethier, Yasiel Puig, Chris Taylor.
The moves leave Walker Buehler, Locastro, Brandon McCarthy, Joc Pederson, Hyun-Jin Ryu, Charlie Culberson and Brock Stewart on the taxi squad (inactive but on-site if an injury replacement is needed).