(Photo credit: Trevor Ruszkowski-Imagn Images)

Not having Jayson Tatum was supposed to make things extremely difficult for the Boston Celtics.

But 30 games into the season, Boston has won 19 and stands in third place in the Eastern Conference. The Celtics take aim at victory No. 20 when they visit the Portland Trail Blazers on Sunday.

Boston has won four straight games and 12 of its last 16 as it enters the second contest of a five-game road trip.

But Celtics coach Joe Mazzulla wants, and expects, more.

'We're not where we need to be,' Mazzulla told reporters. 'But we're getting better, and it's because the guys do a great job of just buying into learning at a high level. And it's a credit to them.'

Tatum ruptured his right Achilles tendon last May during the Eastern Conference semifinal series against the New York Knicks. He is expected to miss most, if not all, of the season.

Co-star Jaylen Brown has stepped up and is averaging a career-high 29.4 points, tied for sixth in the league entering Saturday's play.

Brown has scored at least 30 points in all eight appearances this month while averaging 32.1 points and shooting 43.6% from 3-point range.

Brown scored 31 points on Monday in a 103-95 home victory over the Indiana Pacers and followed that up with 30 during a 140-122 road triumph in Indiana in the second end of a back-to-back on Friday.

Sam Hauser exploded for a season-high 23 points on 7-of-8 3-point shooting in the Friday victory. The seven treys match a season high.

'You make your first couple and it's like human nature, they're going to try to find me a little more,' Hauser told reporters. 'But credit to them, I wouldn't be able to get all these open shots if it wasn't for (Jaylen) drawing all this attention, getting to the lane, making the right read. ... It's really more credit to (my teammates) finding me and getting me the ball when I am open.'

Boston has won the past six meetings with Portland, notching three straight season-series sweeps.

The Trail Blazers have dropped three consecutive games to start a five-game homestand. Portland has allowed at least 110 points in each game.

The Trail Blazers controlled the first half in Friday's game against the Los Angeles Clippers before ultimately falling 119-103.

The Clippers never led until the game was more than 32 minutes old but still outscored Portland by 22 points in the second half.

'I felt really good with the start we had,' Portland standout Deni Avdija said. 'We were engaged, we were locked in. It's a big, big progress from a lot of the (starts). And that third quarter, man, we should have been better in the third quarter. I felt we didn't find our rhythm, really, in the third. They went on a run, we weren't disciplined on defense.'

Interim coach Tiago Splitter said it was a tale of two halves but didn't really have a solid explanation of why the caliber of play was so different.

'It was tough scoring,' Splitter said of the 41 second-half points. 'All the good work we did in the first half when he played fast and moved the ball and moved it side-to-side (didn't continue).'

Avdija had 29 points, nine rebounds and nine assists to lead the Trail Blazers. Shaedon Sharpe added 16 points.

Portland continues to play short-handed. Jrue Holiday (calf) will sit out for the 20th straight game, Jerami Grant (Achilles) will miss his fifth consecutive game and Robert Williams III (knee) will again sit out Sunday due to ongoing injury issues.

--Field Level Media