The Boston Celtics don't have all their issues solved, but they'll be heading into Round 2 on plenty of rest.

Gordon Hayward scored 20 points off the bench and Jayson Tatum added 18 as the Celtics earned a 110-106 win over the Indiana Pacers in Sunday's Game 4 matchup to complete a sweep in their first-round series. Boston will in all likelihood move on to play the Milwaukee Bucks, who have a 3-0 lead on the Detroit Pistons in their series.

The Celtics, their starting lineup in particular, struggled with their shot for much of the contest. Al Horford missed nine of his first 10 shots, ultimately clanking 15 of his 19 attempts from the field to finish with 14 points and 12 rebounds. Kyrie Irving finished with 14 points and seven assists.

Boston was instead saved by its bench, with Hayward and Marcus Morris (18 points) both playing their best game of the series. The Celtics outscored the Pacers by 13 points with Hayward on the floor and by 18 when Morris played. 

The Pacers, as has been the case all series long, could not keep up for four quarters. Five players were in double figures, led by Bojan Bogdanovic with 22 points. However, they shot just 40.9 percent from the floor as a team, including a 10-of-28 mark beyond the arc.

Indiana has lost in the first round each of the last four years.  

Celtics Need More From Kyrie, Starters to Have Chance vs. Bucks

Jayson Tatum: 4-10

Al Horford: 4-19

Kyrie Irving: 4-13

The Celtics starting lineup looked mostly abysmal Sunday. They found no offensive rhythm together and only saw some of their counting stats bumped up by what amounted to garbage-time free throws and buckets. Without the play of Hayward, Morris and Terry Rozier off the bench, the Celtics would be headed back home with a game to play Tuesday.

Fortunately, they were playing a Pacers team that didn't have the offensive firepower to punish them. Even in Indiana's strong runs, it felt like a drowning team fighting just to keep its head above water.

The Milwaukee Bucks are drowners, not drownees. They have the likely NBA MVP, a well-rounded supporting cast that accentuates Giannis' strengths and mitigates his weaknesses and a bench that's every bit as good as Boston's if not better. 

The Celtics are going to have to play to their preseason expectations, rather than their reality, to advance to the conference finals. That begins with their starting lineup.

Irving shot under 40 percent in three of four games against the Pacers. That won't get it done against Milwaukee.

Horford averaged 11.0 points on 34.0 percent shooting against the Pacers. That won't get it done against Milwaukee.

Jaylen Brown finished the series with two solid offensive performances but had eight combined points in the first two games against the Pacers. That won't get it done against Milwaukee.

The Celtics swept the Pacers, which is ultimately a positive outcome. Brad Stevens will have the maximum possible time to scheme and scout how to bring down the Bucks over a seven-game series. But having watched the two teams against equally under-manned opponents, there's a clear chasm in the level of play. 

The Bucks are a significantly better team on both ends of the floor. The Celtics will need more than they've gotten from their stars to pull off the upset.

Pacers Should Focus on Talent Retention Over Rebuild

The Pacers gave eight players 10 or more minutes Sunday. Six of those players (Thad Young, Bogdanovic, Darren Collison, Wesley Matthews, Cory Joseph and Tyreke Evans) are free agents at the end of this season. This was the last time all of those guys will share a floor together.

The impending roster turnover, however, makes Indiana one of the most intriguing teams of this offseason. 

Victor Oladipo's health hangs over everything. If the Pacers feel like Oladipo will miss a significant part of next season, they're a prime tanking candidate. The 2020 draft class is loaded, and the Pacers could choose to bottom out for a year in hopes of landing a co-star for Oladipo. Indiana has no history of bringing in big-name free agents; draft or trade is the only way for the team to take the next step.

If the team expects Oladipo to return near or at the beginning of the season, it might not be a bad idea to run things back. Young, Collison and Joseph should be affordable on short-term contracts, and Bogdanovic played himself into a well-deserved raise this summer. The Pacers should try to wait out the market and hope it dries up enough around their talent that at least the former trio will take a one- or two-year deal. 

The Pacers might internally fancy themselves as contenders for a real difference-maker on the open market, but it's hard to find a match. Maxing out Nikola Vucevic could work, but he's only a slightly better fit next to Myles Turner than Domantas Sabonis. They might be able to get into the room with Eric Bledsoe, but he's approaching 30 and has a history of knee issues.

Going on down the line, every potential fit seems likely to have no interest in coming to Indiana or will require a pay hike to get it done. Tyreke Evans was a sour investment last summer, but it wasn't damaging because it was a one-year contract. There's a cap space bonanza coming this summer; those risky one-year contracts are going to be three years once teams get desperate.

That's why the Pacers should go against the grain and hope they can keep the gang around on short-term deals. 

What's Next?

The Celtics move on to play either the Milwaukee Bucks or Detroit Pistons.