Boston Celtics coach Ime Udoka remains upbeat despite his side losing home court advantage on Sunday, with the Milwaukee Bucks' 101-89 win in Game 1.

Those expecting a defensive slugfest were not disappointed, with both teams managing to restrict the other's offensive sets.

While the Bucks shot a low 41.1 per cent from the floor, the Celtics were almost spectacularly poor on the offensive end, shooting 33.3 per cent (28-of-84) and committing 18 turnovers.

Udoka tried to take the positives out of the ultimate negative, saying his side can only improve as the series progresses.

"Offensively, not the best night," Udoka said post-game. "I felt we guarded them well enough, holding them to one-on-one but to have 89 points and a lack of penetration and paint touches is alarming.

“To lose a 12-point game when we shot so poorly bodes well for us. In a way it’s good to get this dud out of the way offensively.”

In their 4-0 sweep over the Brooklyn Nets in the previous series, the Celtics averaged 34.5 three-point attempts per game.

To underline their inability to penetrate, Boston put up 50 from beyond the arc in Game 1 against Milwaukee, connecting on 18.

Jaylen Brown's three-of-nine from the perimeter to go with seven turnovers for the game was particularly microcosmic, and Udoka believes his side need to make better decisions in their offensive sets.

"As we know, that's what they want to do – protect the paint and make you shoot threes," he said. "We had some open ones, but we played in a crowd too much. That obviously shows in the amount of turnovers – 27 points off 18 turnovers.

"For the most part, I don't think our decision-making was great, whether it was a drop-off or kick-out for threes, but we need multiple [outlets] for penetration, multiple paint touches and they did a good job."