BOSTON, MA - MAY 13: Al Horford #42 of the Boston Celtics is defended by Kevin Love #0 of the Cleveland Cavaliers during the third quarter in Game One of the Eastern Conference Finals of the 2018 NBA Playoffs at TD Garden on May 13, 2018 in Boston, Massachusetts. (Photo by Maddie Meyer/Getty Images)

The Boston Celtics were without two stars, but Al Horford and company almost knocked off LeBron James anyway.

The Boston Celtics, more than any team who made the Conference Finals this year, relied on their whole team to get them that far. Still, Boston’s lone healthy All-Star, Al Horford, certainly showed he deserved that honor in the postseason.

Horford didn’t have the biggest play in the Celtics’ last game of the season, a back-and-forth Game 7 against LeBron James and the Cleveland Cavaliers in the Eastern Conference Finals, but his steady presence kept Boston involved throughout the game.

In 40 minutes of action, Horford tallied 17 points on 12 shots, four rebounds, three assists and one steal. His -2 on the night was the best plus-minus among Boston’s starting five. He was a big part of a defensive effort that held Cleveland to 87 points.

No player had a bigger effect on the Celtics than Horford did across the entire 2018 NBA Playoffs. Boston was 4.2 points per 100 possessions better than their opponents with Horford on the floor, the best mark for any player on the team. Conversely, the Celtics were outscored by 9.7 points per 100 without Horford out there — no player’s absence had more of a negative effect.

That impact is no fluke, despite Horford’s relatively pedestrian per game averages of 15.7 points, 8.3 rebounds, 3.3 assists, 1.0 steals and 1.2 blocks in the postseason. The idea of Al Horford being a good litmus test for NBA fans’ knowledge beyond the stat sheet is not new, but it was certainly reinforced in these playoffs.

The truth is Horford finds ways to make every other Celtics player’s life much easier on both ends. He’s a stout one-on-one defender and an intelligent help defender who helps to coordinate Boston’s top-ranked defense. He can shoot from 3 and from the mid-range, and he can post up as well. Even more important to his positive impact, Big Al can pass from any area on the floor as well.

Like everybody in the non-LeBron bracket, Al Horford is not a perfect player. Sometimes the numbers don’t lie, and Horford simply does not do enough. Twice he failed to reach 10 points against the Cavs, and it’s not a coincidence that the Celtics lost both of those games. Pure points don’t tell the whole story, but on a team missing Kyrie Irving and Gordon Hayward Horford does need to provide more than six or seven points.

Game 7 is another good example of an occasion where Boston could’ve used more offense from Horford, especially late. He scored just three of his 17 points in the second half, on five whole shots. The lone All-Star on a team in Game 7 of a Conference Finals needs to shoot more than that.

Situations like that are a prescient reminder of why the Celtics added Irving and Hayward to their core, aside from the obvious reason that stars are conducive to winning NBA championships. It’s not Horford’s nature to take 25 shots in a game. He’s at his best when he can take good shots and use the rest of his touches to set up teammates.

This version of the Celtics couldn’t overcome Cleveland with Horford doing that. With their two offensive dynamos back next season, Boston will not need so much from Horford. In the same way that Draymond Green isn’t expected to score a ton for the Golden State Warriors, the healthy Celtics won’t have to ask Horford to trade buckets with offensive stars.

The Horford-Draymond comparison is a good one on another level too. Both players have one flaw that tends to drive fans crazy, that is also central to why they’re such good players. Draymond’s pure passion quite possibly lost the Warriors the 2016 Finals, but they’re not a juggernaut in the first place without him leading their revolutionary small lineup defensively.

Horford’s general preference to not take over games via scoring (he only reached 20 points five times in 19 playoff games, and never had more than 26 points this postseason) has hurt the Celtics, but if he did seek out more of his own buckets he wouldn’t be the huge net positive that he is.

And, after all, the Horford-driven Celtics did come very close to knocking off LeBron and making the damn NBA Finals. Credit for that should go to a lot of parties, including Brad Stevens, but Horford was the engine that powered Boston all season long. It’ll be fascinating to see how that looks when he’s got those elite scorers to dish to instead of Terry Rozier and Marcus Morris, as good as those two were at times during Boston’s postseason run.