Newest Dodger is only member of team with something to prove this week

The lone Dodger with something to prove this week, in the long wait for Friday’s playoff opener at Dodger Stadium, is the newest member of the team.

Tim Locastro, the 25-year-old base-running specialist, will take part in a series of simulated games at the ballpark as the team tries to decide whether he can contribute as a member of the 25-man playoff roster.

The Dodgers called up Locastro last Friday for a last-minute audition at Colorado’s Coors Field. Locastro stole a base in his only attempt, and could add another dimension to the Dodgers offense.

“Locastro is a guy who we really have to put eyes on more, and gather more information, for that particular role,” manager Dave Roberts said during a conference call Tuesday night. “All of the other guys who we’re making decisions on, we know what we have in them. A lot of it is just based on the opponent, and how we want to structure the roster.”

The Dodgers do not have to reveal their roster until Friday. And they cannot formalize a group until they know who they are playing. Arizona hosts Colorado in the National League wild card game on Wednesday. Roberts suggested the team had assembled the outlines of rosters for each potential opponent, with the final two or three spots undecided.

Roberts declined to tip his hand on how the Dodgers will fill those spots. He offered praise for veteran outfielder Andre Ethier, who hit .235 in September, but declined to guarantee him a playoff roster spot.

“To say definitively he’s on the roster, we’re not going to do that,” Roberts said. “But we see him as a bat off the bench.”

Roberts delivered similar support for reliever Pedro Baez, who had a 10.38 earned-run average in September but did not permit a run in his final four outings.

“I’m definitely confident that he’s worked out his issues,” Roberts said, adding, “Not sure 100% that we’ve made that decision yet, but if you look at the entire body of work, and the last couple weeks, 10 days, he’s thrown the baseball really well.”

Hill, Darvish to follow Kershaw

Roberts confirmed that Rich Hill, who threw a simulated game Monday, will start Game 2 of the National League division series at Dodger Stadium. Yu Darvish will start Game 3 on the road.

The Dodgers made this decision in deference to Hill’s 2.77 earned-run average at home and Darvish’s 2.44 ERA on the road.

Clayton Kershaw will start Game 1 in the first round for the fifth postseason in a row.

In the other two postseasons of his career, Kershaw started Game 2 of the 2009 NLDS, following Jeff Weaver, and made two relief appearances as a rookie in the 2008 NL championship series.

andy.mccullough@latimes.com

Twitter: @McCulloughTimes