CHICAGO -- Even Mike James couldn't believe he was coming into the game. With 6:20 left in the second quarter, James, the man who was playing in the D League just a few days ago, was being called upon by Bulls' head coach Tom Thibodeau.

[+] Enlarge
Gary Dineen/NBAE via Getty ImagesMike James, above, got the bulk of the minutes at point guard on Thursday, but the Bulls' offense ran through Luol Deng.

"I was shocked when coach called my name," James, the man who re-signed with the Bulls on Tuesday afternoon, admitted after the game. "He said it maybe four or five times ... I had to make him say it one more time just to make sure. But it's all about being ready, it's all about being prepared. When your number is called, you have to contribute however you possibly can."

That's what James did on Thursday night, scoring eight points and dishing out four assists in 17 minutes of play. The best part of James' game won't necessarily show up in the box score, though. James played great defense on Celtics' point guard Rajon Rondo during his time, continually frustrating the guard down the stretch. It was a performance that James took pride in.

"I'm not going to let no one smaller than me post me up," James said. "I take pride in my defense. I'm not the biggest guard, but I have some size on me. I'm not going to let him be able to do whatever. Guards have never posted me up and that's not something new that I'm going to start allowing."

Bulls' center Joakim Noah loves that attitude. He noted that James has already earned a nickname from his teammates because of James' ability to play tough defense in the paint.

"Mike came in and he doesn't play that post me up stuff," Noah said. "Jailhouse basketball. That's what we call him."

Luol Deng has another name for James.

"Mike is a pro," Deng said. "He just came in, we didn't miss a beat ... the rotation is different. Some guys haven't played with Mike, haven't played with him in a while. But he's been running the plays. He wasn't asking 'What play is this?' and all that. That's just what a pro does. He was ready and prepared."

So prepared that he may have given Tom Thibodeau a reason to call for him again in the next few days.