Nuggets coach George Karl isn't one to vociferously debate the merits of playing through an injury, or resting to be ready for the playoffs. He generally feels that if a player can play, he should play. And yet Ty Lawson's situation probably requires a more careful touch. Denver's starting point guard has moved clearly into the category of the team's most indispensable player, particularly given the way the team plays: up tempo all the time; creating havoc on offense and turnovers on defense. Karl doubts that Lawson, who has a strained left heel, will play Friday night against the Brooklyn Nets at the Pepsi Center. Lawson, who received treatment and has missed three of the last four games, was not available for comment. He played 20 minutes during the Nuggets' 100-99 loss at San Antonio on Wednesday, scoring only two points as he struggled without his usual quickness. "Seeing him today, I'd say he probably won't play tomorrow," Karl said Thursday after practice. Karl was asked if he's worried about the injury. "I'm worried because ... a fast player needs his feet," Karl said, then grinned. "If Kosta (Koufos) rolled his ankle, he'd probably be OK. Ty needs his speed to be great."