When Joe Girardi called down for the eighth inning on Monday, Chamberlain stayed idle while Dave Robertson got a double-play grounder on Asdrubal Cabrera and Boone Logan retired Shin-Soo Choo.
Girardi said it would be "a misinterpretation" to say his confidence in Chamberlain has been shaken, but acknowledged he would like to see Chamberlain improve.
"The guys down there know my stance," Girardi said. "I've always talked about, when you're pitching well, you're going to pitch. If it's the eighth inning, there's a good chance I'll go to Joba."
Girardi said that he has been going by matchups of late, but Cabrera was 0-for-5 lifetime against Chamberlain and had never faced Robertson. Girardi said that he liked Robertson's stuff better in the situation against Cabrera.
"My gut told me to go with Robertson there," Girardi said. "I look at more than just numbers. I look at zones and a lot of different things on how we're going to attack hitters. That's what I base my [decisions] on."
Chamberlain has allowed eight runs on 12 hits and four walks in his last five appearances, while Robertson has not been scored upon in his last eight outings. Girardi said he would continue using his bullpen in this manner "until we get Joba right."
"I still have my job," Chamberlain said. "I understand that I can come out and help this team win. Every day, it's a challenge, it doesn't matter what day it is or what situation. You've still got to go out there and pitch well."