The Yankees were able to survive the departure of catcher Russell Martin thanks to the early-season success of Francisco Cervelli.

And their depth was tested again when Cervelli fractured his right hand, sidelining him for six weeks. So far, Chris Stewart has been up to the task of playing on a regular basis.

Stewart helped guide Phil Hughes through eight shutout innings in yesterday’s 4-2 win over the A’s and added his second homer of the season.

“I’m just trying to take care of business behind the plate,” Stewart said. “Whatever I do at the plate is a bonus. If I can go out and do what Phil and I did the first eight innings today and do that every day, it doesn’t really matter what I do at the plate.”

Since Cervelli got hurt during his first at-bat April 26 against the Blue Jays, forcing Stewart into the game, the Yankees have given up more than four runs in a game only once — and that came with rookie Austin Romine catching.

“I had most of these guys last year, so I know what they like to do,” Stewart said.

After backing up Martin a year ago (one homer, 13 RBIs) and spending 2011 as a part-timer in San Francisco (three homers, 10 RBIs), Stewart is rapidly approaching career-best run production.

He turned on a Bartolo Colon pitch leading off the third inning to give Hughes and the Yankees a 1-0 lead with his fourth RBI.