PHILADELPHIA -- The Philadelphia Phillies are sticking with the same team that got them to the NL Championship Series and made no changes to their roster ahead of Game 1 against the Arizona Diamondbacks on Monday night.

The Phillies have 13 pitchers on the roster. They are still undecided on who starts Game 4 on Friday night.

They had 15-game winner Taijuan Walker and Cristopher Sánchez each throw two innings of a simulated game Sunday, so they remain in contention for a Game 4 start.

With two short series, neither starter has pitched this postseason.

Thomson said the decision could come down to how much the Phillies have to use their bullpen over the first three games. Sánchez has extensive experience as a reliever, while Walker, in the first season of a $72 million, four-year deal, has made 194 career starts.

The Diamondbacks, who won all five postseason games to reach the NLCS, also largely stayed put. They added right-handed pitcher Slade Cecconi to the NLCS roster and left off infielder Jace Peterson. That gives Arizona 13 pitchers.