PHOENIX -- While the Dodgers swept a pair of games from the D-backs in Australia to open the regular season, pitchers Zack Greinke, Dan Haren, Josh Beckett and Brandon League were left behind in Arizona to continue Spring Training.

Combined, the quartet has opened the season 13-4 with a 2.42 ERA, which begs the question: What the heck was going on at Camelback Ranch in March?

"We just wanted to get them on track, and keep them there," said pitching coach Rick Honeycutt.

Each of the four pitchers had dealt with a spring physical issue. Greinke strained a calf muscle. Beckett, already coming off thoracic outlet surgery, bruised his thumb on a clubhouse door. League missed time with a lat strain. Haren had the typical aches and pains of a 33-year-old pitcher who rushed into shape to be ready for Australia if needed.

Because only two starters were needed overseas, the Dodgers made Greinke and Haren two of the three designated players exempted from the trip roster, along with League, who had the added issue of a mechanical flaw dogging him from last year.

Honeycutt, assistant coach Ken Howell and bullpen coach Chuck Crim set up a program of bullpen sessions and Minor League games so the four pitchers would be ready to rejoin the club after a week abroad. Howell stayed behind in Arizona with the four veterans, working with Minor League coaches Rick Knapp, Charlie Hough, Scott Radinsky and Rafael Chaves.

Everybody take a bow.

Greinke (6-1, 2.38) is tied for the league lead in wins. Haren is 5-1. Beckett's opponents' batting average is .199. League, who struggled to a 5.30 ERA last year, now has a mark of 1.59 and hasn't allowed an earned run in his last 11 appearances.

Greinke, who starts for the Dodgers against the D-backs in Friday night's series opener, said the extra time in Arizona wouldn't have mattered if he had been healthy. But it was crucial in his recovery from the calf muscle strain.

"If I had gone, Australia would have been a mess for me," Greinke said. "Technically, I would have had enough starts to be ready to open the season. But it would have been very tough. Staying back helped me catch up with the workouts."

Beckett and Haren said their personalized training programs in Arizona were contributing factors in their sharp start.

"It was really relaxing," said Haren. "We were able to throw our bullpens, pitch in the Minor League games, had plenty of time with the training staff. It was a nice pace, and I needed it. We did our work, but didn't have to do a million drills.

"I know Brandon was able to work out things mechanically and with his mindset. I think it was great for all of us."

Beckett said he needed the time for his bruised thumb to heal. The soreness prevented him from flipping his curveball, which has turned into an unexpected weapon he's never really utilized until this year.

"Having Kenny, Chavy and Charlie, we were all able to work on things we needed to work on," said Beckett. "For me, it was the offspeed stuff."

Howell said the focus for the starting pitchers was to build up their arms, not only in pitch count, but in the ups and downs of one inning to the next.

"With the Minor League games, we were able to control that by cutting off an inning at 10 pitches to make sure they could get enough innings," he said.

The real project was League, who had allowed five earned runs in three appearances when the club left for Australia, looking a lot like last year's version, which was a bust after signing a three-year contract.

But Howell said Honeycutt noticed League's arm slot had crept up to nearly overhand compared to the three-quarter delivery that earned him the contract.

"Brandon had gotten too conventional," said Howell. "When he's at his best, his ball goes to the side and has run. Now that his arm slot is lower, he's getting ground balls instead of fly balls. And his confidence has come along with the success. No doubt staying back was beneficial to him."

The Dodgers have won all five road games against Arizona this year, both games in Australia (technically D-backs home games) and a three-game sweep at Chase Field in April.