The harshest critic: Antetokounmpo, himself.

He took only 10 field-goal attempts, his third-lowest total of the entire season. Antetokounmpo still had a brilliant stat line, finishing only one assist shy of a triple-double, but the Bucks lost 92-87 and now go back to Milwaukee trailing the first-round matchup 3-2.

Game 6 of the Celtics-Bucks series is the lone matchup on the Thursday night NBA schedule.

“Game 6, I’ve got to come out and be more aggressive,” Antetokounmpo said. “It’s on me. I had open shots, but they weren’t my shots so I didn’t feel comfortable taking them. … I’ve got to be more aggressive, make more plays because definitely, my teammates need me.”

It’s not like he was choosing to not be involved.

The Celtics got Marcus Smart back for Game 5, and Boston is much better defensively when he’s on the floor. Open looks seem to happen far more infrequently when Smart is out there, and the Bucks must solve that riddle or else their season is about to end.

Smart wasn’t the only defensive hero for Boston in Game 5. The Celtics put Semi Ojeleye on Antetokounmpko, and it worked as well as Boston could have hoped.

“Giannis is a heck of a player,” Celtics coach Brad Stevens said. “You’re not going to be perfect against him. You’re not going to hold him down by any means. He makes plays for other people, he’s very unselfish … but we just felt like we needed a little bit more ball pressure overall, and so that was the decision to go smaller.”

If Antetokounmpko doesn’t come up bigger Thursday, it’ll be Boston going to the second round.

Here’s some of what to know going into Game 6:

CELTICS AT BUCKS

Boston leads 3-2. Game 6, 8 p.m. EDT, TNT

NEED TO KNOW: Since 2002, there have been 29 NBA teams with at least one postseason series win to their credit. The lone exception: The Bucks. It’s been 17 years since the Bucks advanced to the second round, and the Celtics are on the cusp of adding another year to Milwaukee’s wait. So far in the series, Milwaukee has outscored Boston 520-519 — which would indicate that it’s been a super-close matchup. That’s not the reality. There have been wild ebbs and flows, with one team leading by 16 points at some point in each of the last four games.

KEEP AN EYE ON: Free throws. Boston is 99 for 130 in the series from the line, while Milwaukee is 68 for 100. The Bucks have been called for 30 more fouls in the series, 124-94 — which works out to six more per game.

PRESSURE IS ON: Clearly, the Bucks. They’re facing elimination, of course, so there’s the pressure. Antetokounmpko was on the Milwaukee team that won two elimination games against Chicago in 2015 (before the Bucks eventually lost that series in six games). And he also remembers the sting of last season, when the Bucks went home for Game 6 trailing Toronto 3-2 and wound up letting a pair of late leads slip in what became a season-ending loss.

INJURY UPDATE: Getting Smart back was a rare bit of good news for Boston in this injury-marred season, one where the Celtics have been without Gordon Hayward since opening night and ultimately lost Kyrie Irving for the playoffs. Smart hadn’t played in about six weeks after tearing a ligament in his right thumb, but was a clear difference-maker for the Celtics in Game 5.