The Hawks were minutes from making it to the second round of the NBA playoffs with relatively few injury issues when Kirk Hinrich crumpled to the floor and clutched his right leg.

The Hawks said their starting point guard is doubtful to play in the Eastern Conference semifinals against Chicago after suffering a “significant strain” to his right hamstring Thursday. Hinrich sustained the injury late in the Hawks’ series-clinching victory against Orlando at Philips Arena.

Hinrich’s injury is a major blow to the Hawks’ prospects against the top-seeded Bulls. He’s best suited to defend All-Star Derrick Rose, and the Hawks also could use Hinrich’s shooting against the league’s best defensive team.

The Hawks were hampered by injuries while being swept 4-0 in the second round of the past two playoffs. Now they are likely to be without Hinrich against the Bulls.

“That’s tough,” Hawks guard Jamal Crawford said Friday before the extent of Hinrich’s injury was announced. “Kirk is the head of our defense. He’s the guy who makes stuff happen from the start. I just hope he is healthy enough to get out there.”

Hinrich suffered the injury while scoring on a drive with about three minutes remaining in Game 6. He limped down the court to play defense before collapsing at the next stoppage of play.

The Hawks said an MRI on Friday revealed the strain.

Hinrich is so central to Hawks fortunes against Chicago that Drew said Friday that he and his staff couldn’t put together game plans until his status was clearer.

“It certainly changes things [if Hinrich is out],” Drew said. “Hopefully he will be able to go, but if he’s not, we will have to make an adjustment. Not knowing what we will do at that point, we will talk about it as a staff and then make a decision.”

Drew’s options to replace Hinrich in the starting lineup include Crawford or Jeff Teague. Crawford is a below-average defender. Teague is the team’s quickest player, but he never cracked Drew’s playing rotation this season.

Drew said guard Joe Johnson and swingman Damien Wilkins also could spend time defending Rose.

The Hawks acquired Hinrich as part of a trade with Washington in February. The team made the move because it believed Hinrich’s predecessor, Mike Bibby, had become too much of a defensive liability.

Hinrich said he was glad to leave the struggling Wizards and join a playoff team. After a shaky stretch of games to end the season, Hinrich showed his worth in the series against Orlando.

Hinrich helped corral Magic point guard Jameer Nelson. His ability to slow dribble penetration and cover ground to challenge shots was key to the team’s pick-and-roll defense.

Hinrich averaged 10.2 points in the series while shooting 50 percent, the best mark among Hawks regulars. His knack for creating space with his dribble allowed him to get open shots without the benefit of screens or plays called for him.

Drew said Hinrich was in good spirits Thursday night after the game and also Friday morning before departing for the MRI. If Hinrich is unable to play, he still could help his team’s efforts to scout Chicago.

The Bulls selected Hinrich with the No. 7 overall pick in the 2003 draft. He played in Chicago until the team traded him to Washington last summer. Hinrich played alongside five current Bulls players.