Vazquez had turned his season around after a sluggish beginning, but his August has been rough. Battling diminished velocity, Vazquez is 0-2 with a 8.10 ERA in four starts this month, and he has not made it through five innings in any of his past three outings.
"I'm disappointed, obviously, but I'm also not doing my job, so I understand that part," said Vazquez, who will be available in relief beginning on Wednesday night against the Blue Jays.
Nova showed the Yankees a measure of toughness in his 5 1/3-inning no-decision on Monday, limiting Toronto to two runs -- both coming on a Jose Bautista homer -- and six hits in an outing that also included a benches-clearing incident.
Girardi pointed to a pressure-filled situation during the first inning in which Nova, staring at Vernon Wells with the bases loaded and no outs, could have caved, but the right-hander benefited from a double play and escaped the inning without letting a run score.
"Nova threw pretty well last night, and we think his stuff is even better than what he showed last night," Girardi said on Tuesday.
Girardi said that the Yankees are not inclined to use a six-man rotation, but their hope is that rest will help Vazquez cure what has ailed him in recent outings, as he has fallen behind hitters and struggled to show consistency.
A brief transition to the bullpen helped in May, when Vazquez picked up a one-out win in relief against the Red Sox and proceeded to go 5-3 with a 2.78 ERA in his next 10 starts.
"I think the last time, it was more mental than any other thing," Vazquez said. "This time, it's just that I'm not doing my job. I feel good physically and mentally, but I'm not throwing the ball well.
"The last time they put me in the 'pen, it was only one day, but that one day helped me out a little bit. Hopefully, this time it will, too."
-- Bryan Hoch