Demar DeRozan was a man looking for answers after his Chicago Bulls were handed a demoralising 126-98 defeat at the hands of the reigning champion Milwaukee Bucks.

DeRozan, who at one stage this season was considered a real MVP candidate, had a sub-par 23 points on 23 field goal attempts in the loss, which moved the Bulls to a record of 3-9 in their past 12 games.

Three of the Bulls' past four games have now resulted in losses of at least 15 points against strong playoff contenders in the Utah Jazz (125-110) and the Phoenix Suns (129-102) before Tuesday's loss to Milwaukee.

Speaking to post-match media, DeRozan said it was evident what makes the Bucks a great team.

"Playing against the defending champs – seeing, feeling, understanding how hard they compete, and how well they execute," he said.

"Their physicality, everything that comes with it, it's how they got what they deserved last year, so that's what I take away from [this game].

"It's definitely not a talent issue at all – we've proven we are a great team – it's just execution, especially when you're playing against top-notch teams that understand the value of executing on both ends, and understand their assignments every time they stop out on the court.

"Those teams are always on a string, and we show it through spurts through a game, but the good teams that go far do it as close to 48 minutes as possible – not just a quarter, or half a quarter.

"You need to be as close to perfect through a 48-minute game as possible."