Josh Hart left Game 5 in the fourth quarter, did not return to the bench, and now the Knicks have to see whether their CJ McCollum coverage still travels into Game 6.
The 126-97 win makes this easy to undersell. New York is up 3-2, Jalen Brunson had 39, and the series can look like it has already chosen a direction. But a closeout game usually starts with the opponent poking the matchup that looks least settled.
For Atlanta, that is McCollum's first action. If Hart plays and moves normally, the Knicks can keep a body attached through the turn, avoid emergency help from the corners, and keep the rest of the floor in order. That matters because defense is connected to Brunson's night, too. When New York is not scrambling, Brunson can start possessions from normal spots instead of dragging the offense out of chaos.
If Hart is limited or out, the first problem will show up before McCollum's box score changes. Watch whether McCollum catches with daylight. Watch whether he turns the corner without feeling a chest. Watch whether the Knicks have to switch late, send help early, or give up the next pass because the first defender cannot stay attached.
That is how one injury note becomes a basketball problem. The rotation starts a beat sooner. The rebound gets harder because a help defender has already left his man. The Hawks get a cleaner second side. Suddenly the Game 5 blowout is not the Game 6 possession map.
A steady Knicks night would be pretty obvious: McCollum stays bottled up no matter who starts on him, Hart's minutes either look normal or the fallback defender holds the same pressure, and New York finishes enough possessions without cross-match confusion. In that version, Hart's back is a concern, not the hinge.
The dangerous version is McCollum creating early-clock advantages over and over, forcing New York to borrow help from places it did not need to in Game 5. Then Brunson's 39 matters, but it does not erase the cost. The Knicks can still close the series. They just cannot treat Hart's questionable tag like a footnote if McCollum is the first guard Atlanta uses to test the floor.