Jayson Tatum, sporting his Kyrie 4 Nikes, drives to the rim in front of LeBron James during Boston’s Game 5 win Wednesday. (Greg M. Cooper/USA Today Sports)

BOSTON — There was a Kyrie Irving sighting in Game 5, but merely on his teammate’s feet.

While Boston Celtics rookie Jayson Tatum continued his breakout postseason run Wednesday night, leading his team in scoring and inching closer to the NBA Finals, he wore green Kyrie 4 Nikes. He paired the shoes with fluorescent yellow laces that could be seen from the upper bowl of TD Garden.

Just as visible throughout the Eastern Conference finals is the impact that the absence of Irving, the five-time all-star point guard, is having on the series. Just not for the Celtics, who stretched a homely performance into a 96-83 win and a 3-2 lead in the best-of-seven series.

April’s season-ending surgery for Irving, who spent three seasons as James’s sidekick in Cleveland before requesting a trade last summer, has influenced Boston in many ways, even though his gritty teammates can close out the Cavaliers on Friday. Cleveland, meanwhile, could use Irving now.

LeBron James received no help Wednesday from even his most trusted teammates. Three starters (George Hill, J.R. Smith and Tristan Thompson) combined to score 10 points on 2-of-14 shooting while Kevin Love contributed only four of his 14 points in the second half.

The Cavaliers needed those four just to equal Tatum’s total; he finished with a Celtics-high 24 points and exceeded 300 points for the postseason. Tatum became only the sixth rookie in NBA history to reach the milestone, and the first since 1978.

Around Tatum, the Celtics were mediocre. The team leaned heavily on defense while misfiring on the offensive end (36.5 percent). Its dry stretches swung the door open for Cleveland to charge in and potentially steal the game. But Boston prevailed because it had strength within the starting five, as well as backup from the bench, with Marcus Morris and Marcus Smart each chipping in 13 points.

“It took a team full effort,” Smart said.

While James poured in a game-high 26 points, he looked efficient in some ways (11 of 22 from the floor), sloppy in others (six turnovers) and thoroughly overmatched as a solo act.

Boston has figured out how to play and win without Irving. Cleveland, in its worst performances, has lacked the offensive gusto the dynamic point guard can bring to the court.

“We were very stagnant, not moving the ball the way we did at home,” said Thompson, who missed his three field goal attempts and finished with one point and six rebounds. “We can’t get away from that. I think we’re a much better team when we move the ball. Can’t get it flowing.”

That’s one way of looking at why only two Cavaliers players scored in double digits. Cleveland’s anemic play in Boston, however, continued a trend from previous road games.

In Game 1, the Cavaliers trailed by 29 points. In Game 2, the starting backcourt of Hill and Smith combined for only three points. Wednesday, Cavaliers Coach Tyronn Lue noticed slight fatigue in James and pulled him with 1:56 remaining in the third quarter.

“He looked a little tired to me, yes,” Lue said.

The substitution magnified the ugliness in the game as the teams wasted nine consecutive possessions before the horn.

With the score stuck on 76-60 in Boston’s favor and James having played 32 minutes and needing a rest, the Cavaliers started the fourth quarter with Smith, Jordan Clarkson, Kyle Korver, Jeff Green and Larry Nance Jr. on the floor. Note the absence of an all-star or even a point guard.

James, leaning back in his folding chair and fiddling with his beard, watched the start to the fourth quarter. When Nance committed an offensive foul on the first possession, players on the Cavs bench leaped to their feet to protest the call. James never moved. After Smith bricked a catch-and-shoot three-pointer, James eventually stood up and walked toward the scorer’s table.

Momentum quickly shifted as James helped orchestrate a 9-0 run and the Cavaliers pulled within 83-71. But the short-lived surge ended with a mess of missed shots.

Around the three-minute mark, James launched a deep three-pointer. As Tatum cleanly secured the rebound, James backpedaled while spreading his arms and shaking his head. What could have been going through his mind? Only James knows.

After the game, he was asked how Cleveland has prepared for a challenge like Friday’s potential elimination game, its first since winning Game 7 against Indiana in the first round. Echoing a night spent receiving little assistance from his teammates, James answered the question with an independent outlook.

“Everybody is different. I know how I prepare myself. I know how I prepare going into each and every game, no matter if it’s elimination or 0-0, whatever the case may be in a playoff game,” James said. “So I can speak for myself and know what my mind-set will be on just trying to help us, like I said, do every facet of the game, to try to extend the series. We’ll see what happens.”

More on the NBA playoffs:

Fancy Stats: Irving’s absence isn’t hurting the Celtics. It’s crushing LeBron’s Cavaliers.

Rockets draw even with Warriors in Western Conference finals

Only Steph Curry can make the Warriors the most dangerous version of themselves

The NBA Finals blueprint for the Cavs, Celtics, Rockets and Warriors