Mike Budenholzer says the Milwaukee Bucks showed their strength in depth by reaching the Eastern Conference playoff semi-finals without Khris Middleton.

The defending champions beat the injury-hit Chicago Bulls 116-100 in Game 5 at Fiserv Forum on Wednesday to advance from the first round of the postseason.

Middleton sprained the medial collateral ligament in his left knee during the fourth quarter of Game 2, but the Bucks proved they could cope without the All-Star.

Budenholzer confirmed Middleton will miss the start of the playoff semi-final series against the Boston Celtics.

But the Milwaukee head coach is confident other players can continue to step up in his absence.

"We've been talking about the depth of the roster, the quality of the roster, a lot this season," Budenholzer said.

"Other guys have gotten opportunities and played well. Our defense has tightened up, and we've leaned hard on that these three games. We've got depth. We've got a good group.

"We miss Khris; I don't think anybody underestimates how important and how effective he is for us. While we don't have him, we've got to be our best all up and down the roster."

Giannis Antetokounmpo played a big hand as the Bucks ended the Bulls' season, putting up 33 points and nine rebounds in Game 5.

The two-time MVP said being "desperate" to get the job done in the absence of Middleton was vital.

"After Game 2, the team knew what the deal was," Antetokounmpo said. "We knew what we had to do, we had to be desperate.

"We had to go out there and compete at a high level. Pay attention to detail as much as possible. Help one another defensively. We've got to do it as a team. It's not a one-man show or two-man show.

"Now we're going to a different series, playing a different team, a very, very good team, and hopefully we can do it again."