The Celtics – or what’s left of them, anyways – return to the TD Garden Thursday with their playoff lives on the line.

After five games against the Atlanta Hawks, it’s been the home team’s series. Boston needs that to continue, or they’ll be making offseason plans sooner than they’d hoped.

The good news? The Celtics look like a completely different team in Boston than they do in Atlanta. Last weekend, the C’s took both games in Boston against the Hawks thanks to Isaiah Thomas in one game, and a complete team effort in the second game (with Marcus Smart leading the way).

So how do the Celtics avoid elimination and force a Game 7 back in (gulp) Atlanta? Here are three main factors.

Tape everything up and hope for the best

Unfortunately for the Celtics, their biggest issue is one they really can’t control at this point: health. Avery Bradley has missed Game’s 2-5 and if you’re holding out hope he’ll play in Game 6 or a possible Game 7, give it up. Jae Crowder and Kelly Olynyk haven’t been the same since suffering injuries in the regular season, either. But the most concerning injury now has to be that of Isaiah Thomas, who suffered a “mild” sprained left ankle in Game 5, the second time he’s tweaked it in as many games. On top of that, his foot is messed up. The Celtics go as Thomas goes, and while he’ll certainly play, it remains to be seen how effective he’ll be.

Who’s going to bail out Thomas?

It was obvious what the Hawks did to stymie the Celtics offense in Game 5: They took Thomas out of the game by swarming him every time he touched the ball. That partially explains his season-low seven points. Thomas was quick to point out after the game that when that happens, his teammates have to make the Hawks pay. If two or three Hawks are on Thomas, there are open Celtics players. Evan Turner, Crowder, Smart, and Jonas Jerebko all have to do their parts on offense in order for this thing to work. Don’t expect another 40-plus scoring game from Thomas.

Start fast and don’t look back

The Celtics can’t seem to hit shots in Atlanta. Through three games, they’re shooting an abysmal 23.9-percent from the field in the first quarter. Those kinds of starts equal losses. In Boston, that number jumps to 46.7-percent. It’s not rocket science, folks. If the C’s can get off to a good start and keep the fans engaged, they can put that fear back into Atlanta that we’ve seen in this series. But if they instead allow Paul Millsap or Kyle Korver to get hot early, it’ll be another first round exit