GLENDALE, Ariz. -- The Dodgers open the Cactus League season this Saturday, and manager Dave Roberts has the weekend's starting pitching mapped out.

Ace left-hander Clayton Kershaw is slated to pitch an inning against the White Sox at Camelback Ranch in Saturday's opener. Game time is 12:05 p.m. PT; watch it live on MLB.TV. Rich Hill is scheduled to start Sunday, while Kenta Maeda will pitch Monday.

If that trio remains healthy, they will fill the top three slots in the rotation when the regular season opens with a four-game home series against the Padres from April 3-6. But that fourth game? Right now, that's anybody's guess.

Roberts won't be ready to discuss the back end of the rotation for a while. But with eight consecutive games to open the season -- and 16 in the first 17 days -- the Dodgers definitely will need a fifth starter right away.

"I think that when we get toward the second week of March, things have got to line up," Roberts said on Thursday. "But right now, we want to make sure guys get innings, whether they're pitching on the main field or the back field. We just want to make sure guys get their work in."

The Dodgers have no shortage of candidates for those final two spots, many of them having suffered an injury-plagued 2016 season. Or in the case of Hyun-Jin Ryu , two seasons down after left shoulder surgery. Brandon McCarthy (Tommy John surgery), Scott Kazmir (spine inflammation), Alex Wood (left elbow surgery) and 20-year-old Julio Urias are also in the mix.

Urias is the most obvious selection. The left-hander is healthy coming off a rookie season in which he went 5-2 with a 3.39 ERA over 18 games (15 starts), with 84 strikeouts and 31 walks.

Roberts said he -- and the club's baseball operations department -- have some thoughts on the two remaining rotation spots, in what currently amounts to a left-handed-heavy rotation.

"We have an idea," Roberts said. "We're not prepared to share it right now, but we have an idea."