The Nationals took a significant step toward setting their 2012 starting rotation Thursday afternoon, finalizing a one-year contract with right-hander Chien-Ming Wang, a team official said. The deal, pending a physical, is worth $4 million plus performance bonuses.

(Jacquelyn Martin/AP)

Wang did not return to the majors until late July this season, at which point he made 11 starts and went 4-3 with a 4.04 ERA, his sinker improving and confidence soaring as the season wore on. He made $1 million in base salary and earned roughly $2.5 million more in incentives.

Wang has often cited the Nationals’ support as a motivating factor to re-sign with the team. An important person behind the scenes in Wang’s recover was Nationals pitching rehab coordinator Mark Grater.

Reached by phone Thursday, Grater estimated he and Wang spent roughly 500 days together in Viera, Fla., as Wang sweated through a grueling rehab.

“It’s hard to compare to anybody,” Grater said. “I don’t think anybody has had this surgery and been able to throw a baseball competitively, the way he did last year. He’s a unique individual. His work habits, his thought process. He would arrive 9 o’clock, and he’d be leaving the ballpark at 2:30. You don’t see that too often.

“He’s come a long way. He worked hard. I’m glad to see that we signed him. We reaped the rewards. Now it’s up to him. The hard work paid off.”

When Wang made his first start in late July, the Nationals flew Grater to Washington so he could watch from a suite at Nationals Park, which he called, “one of the nicest things I’ve ever done as a coach.”

With Wang in the fold, the Nationals would have a capable starting rotation even if the offseason ended today. With Stephen Strasburg, Jordan Zimmermann, John Lannan, Ross Detwiler, Brad Peacock and Tom Milone all under team control for 2012, the Nationals have the pitching depth to possibly trade a starter for the center fielder General Manager Mike Rizzo desires.

Even with Wang signed and their considerable depth, the Nationals are likely to try to sign a free agent pitcher. Individuals with ties to the Nationals expect them to pursue Chicago White Sox free agent Mark Buerhle, and the Nationals have also scouted Texas Rangers free agent C.J. Wilson and Japanese superstar Yu Darvish.