"It doesn't really matter to me," Robertson said. "I've been back and forth between [innings] -- six, seven, eight, all sorts of things. It doesn't really matter to me because it's not my decision to make."
Yankees manager Joe Girardi said that he isn't prepared to be tied down to a single closer in the wake of Mariano Rivera's season-ending right knee injury.
Girardi promised that Rafael Soriano would see time in the ninth inning as well, but for the purposes of Friday's contest -- the first without Rivera -- Soriano warmed up in the eighth inning and Robertson entered for the ninth.
"I'm going to go out there and do the same thing I'd do in the eighth, sixth or ninth," Robertson said. "I'm going to go out there and get outs. That's the bottom line."
Using what catcher Chris Stewart called a "disappearing fastball" that sneaks up on hitters, Robertson has struck out each of the last eight batters he has faced and 10 of the last 11 as he has compiled 12 scoreless innings to begin the season.
"His command has been better," Girardi said. "He can get in some three-ball counts, but he's been able to make pitches when he's done it. I think it's just the experience has probably helped him get away from the walks. It's important, in the role that we ask him, that it continues."