Dodgers’ starting rotation is a high-wire, high-risk act

Zack Greinke hasn’t complained of any elbow problems for the last several weeks.

The Dodgers right-hander certainly pitched as if nothing was wrong Tuesday night, when he made his season debut in what became a 7-3 loss to the San Diego Padres at Dodger Stadium. He was charged with a run in the first inning when Carl Crawford misplayed a ball in left field, but otherwise blanked the Padres, whom he held hitless over the next five innings.

The Dodgers led, 2-1, when Greinke left, but it was 3-3 going into the ninth, whereupon the Padres scored four times.

As dominant as Greinke was for the six innings he was on the mound, these remain unsettling times for the Dodgers and their rotation.

Greinke didn’t have a completely normal spring training, which, in itself, shouldn’t be a reason for concern.

He experienced some discomfort in his arm in his first camp with the Dodgers, but made 28 starts in 2013. If not for the broken collarbone he suffered in his second start of that season, he would have made more.

He was sidelined with a strained calf last spring, but went on to make 32 regular-season starts.

At the start of camp this year, Greinke received what was described as a lubricating injection in his right elbow — the same elbow that delayed a start in August last season by two days. However, once he resumed throwing, he maintained a normal program, which, under most circumstances, would make his health no more of a concern than anyone else’s.

But these aren’t normal circumstances, as the team’s new front office has gambled the fortunes of a $270-million roster on a rotation that could be under constant threat of breaking down.

Suddenly, Greinke’s reliability isn’t something that can be taken for granted. It’s essential.

Already, Hyun-Jin Ryu is on the disabled list with shoulder inflammation. Ryu landed on the disabled list twice last season with the same issue.

On Tuesday, Ryu played catch for the first time since he was shut down two weeks ago. But there’s no indication the Dodgers have identified the exact source of Ryu’s discomfort, which has some insiders wondering if the problem will return once he resumes pitching.

“I’m concerned about him,” Manager Don Mattingly acknowledged. “I’m concerned about everyone, honestly.”

He should be.

Brandon McCarthy has pitched 200 innings in a season only once in his career and that was last year. Brett Anderson has pitched fewer than 100 innings in each of the last four seasons.

“I just look at the other side of that,” Mattingly said. “I look at the upside. You see Brett throwing the way he’s capable of. That’s No. 1-, No. 2-type stuff. The same with Brandon.”

The bets the Dodgers have placed on McCarthy and Anderson were carefully calculated. They attributed McCarthy’s breakout season to a new strength program that was said to reduce pressure on a once-problematic shoulder blade.

In Anderson’s case, they observed how the left-hander’s recent injuries weren’t arm-related.

“You know the upside and you know the downside,” Mattingly said. “Certain things you can’t control.”

Greinke’s performance Tuesday night offered reasons to be optimistic. The All-Star looked like the same pitcher who was a combined 32-12 with a 2.68 earned-run average over the previous two seasons, if not better.

Greinke gave up a two-out single to former teammate Matt Kemp, who scored when Justin Upton hit a liner to left field that evaded the glove of a sliding Carl Crawford. Upton’s would-be single was scored as a triple and he was credited with a run batted in.

Upton was stranded on third base, as Greinke struck out Will Middlebrooks to end the inning.

Over the next five innings, only two Padres reached base.

The first, Alexi Amarista, was the beneficiary of an error by shortstop Jimmy Rollins.

The other, Kemp, drew a two-out walk in the sixth inning.

Follow Dylan Hernandez on Twitter @dylanohernandez