CHICAGO -- It was nearly the biggest shot the Brooklyn Nets took all night, and it happened before anybody even took the court.

Joe Johnson took a pregame cortisone injection in his ailing left foot, allowing him to play 40 minutes Thursday that otherwise would have been impossible, yet it went for naught as the Nets' rally fell short in a 79-76 playoff defeat to the Chicago Bulls.

"I got [the injection] a little bit before the game and it definitely helps, it definitely works, and that was the first time we've done it," said Johnson, who aggravated an old plantar fasciitis injury in his left foot during Monday's Game 2. "[The shot] was a little painful, but you have to do what you have to do sometimes."

Johnson was far from explosive, but managed to shoot 6-of-14 from the field for 15 points, while also contributing three assists and three rebounds. For most of the night, he was matched up against the Bulls' Jimmy Butler, who had just four points on 1-of-5 shooting.

Now comes the telling moment. If playing in Thursday's game caused an even bigger setback, more will be known Friday. Plantar fasciitis is known to reveal itself the day after activity.

"It's a little sore, but that was expected," Johnson said. "This was definitely a tough loss for us tonight."

Johnson insisted during the game that he felt fine, so Nets coach P.J. Carlesimo felt comfortable extending his minutes.

"He was asking me how I felt, and I told him, 'Good,' " Johnson said. "I felt pretty good the whole game other than probably about the last two to three minutes. It kind of tightened up. But other than that, I felt all right."

Johnson, who has averaged 16 points in the three games of the series, didn't participate in the morning shootaround but had every intention of playing. He considered the cortisone shot a no-brainer.

"I had no choice," he said. "I couldn't have played without it."