All an elongated hamstring means is an overstretched hamstring with really means, hamstring strain.
I would guess that it depends on how he feels as if he is warming up. I would think that Sevening will monitor everything about him and make sure that he's prepped to play. While he is playing, the monitoring continues. If something seems off, then they'll pull him, he then may or may not come back for the rest of game 4. I think for Game 5 with the added day off and the treatments, he should be back to almost full strength.
Let's Have A Black Celebration!!!
-Depeche Mode 1986