After late loss to Sixers, the question remains ... What happened to the Celtics' elite defense?

Ever since Brad Stevens has had some talent (ie. post-2015) to work with at the NBA level, his teams have primarily been stellar on defense. Boston has had a top-five defense for two of the past three regular seasons and they still rank sixth overall this year on paper, allowing 104.7 points per 100 possessions.

Yet, even ahead of the Celtics surrendering 118 points to the 76ers on Wednesday night, Stevens was not a believer in his team’s defensive prowess even as the numbers that indicated that this team was well above-average on that end of the floor.

“I still can’t believe where we’re ranked, that’s not what my eyes tell me,” Stevens explained. “I still don’t think we’re as good a defense as our ranking. It’s something that we really need to improve in the next month.”

Stevens' eyes do not deceive him. For the past two months (since February 1st), the Celtics have been the 20th-best defense in the NBA, allowing 109.6 points per 100 possessions, five points worse than their season average. They are the worst defensive playoff team in the league over that stretch and they’ve been consistently this bad for nearly a third of the season (21 games). To make matters worse, they have been even worse in the fourth quarter than full games over that stretch. Their defensive rating balloons to 112 points per 100 possessions in the final frame (seven points worse than their season average), which has been a crucial factor in the team’s pedestrian 11-10 record since February 1st.

There have been all kinds of contributing causes to the defensive dropoff during this span from injuries (Aron Baynes) to effort issues (Kyrie Irving pre-plane ride) to periodic lapses (Jaylen Brown, Jayson Tatum against Denver). However, one major glaring issue continues to slide under the radar, at least when it comes to minutes distribution and this problem was on full display throughout the fourth quarter of Wednesday’s loss to the Sixers.

The issue? Marcus Morris has been dragging down Boston’s defense on a nightly basis for the past couple of months.

This obviously hasn’t been a year-long problem with Morris. He was arguably the team’s most consistent player during the first half of the year with his superb shooting, terrific defensive rebounding and steady play. However, the whispers of Morris playing at an All-Star level seem like ages ago. The veteran forward battled a shooting slump for a while and was not great in that department on Wednesday either (four points on 2-of-9 FG). However, the bigger issue with the 29-year-old has been on the defensive end for the past two months. Quite simply, the Celtics have been a horrendous defensive team most of the time he’s on the floor.

Over the past 21 games, Boston is allowing 113 points per 100 possessions when Morris on the court, which is the worst mark on the roster. His net rating (-7.5) is dead last on the team as well. The Celtics are a better team on both ends of the floor when he’s not in the game and yet he’s played the fourth most minutes on the team over that stretch.

Those negative trends continued on Wednesday night in Philadelphia. Morris had the worst defensive rating on the team (133 points allowed per 100 possessions) in his 35 minutes. The team allowed just 74 points per 100 possessions when he was on the bench. It’s fair to cut some slack to Stevens for the heavy minutes load given to Morris on Wednesday due to the injury to Baynes and ejection of Marcus Smart. Against the size of the Sixers, Stevens really had no choice but to go with Morris or Semi Ojeleye down the stretch, unless he wanted to stay super small with Terry Rozier.

Stevens stuck with Morris and his fingerprints were all over this late collapse as Boston blew a nine-point lead in the fourth quarter. A few of the glaring examples of Morris hurting the defense can be seen here:

8:40 remaining: Celtics lead 99-90

Let’s start with some overhelping and a lack of awareness. Tobias Harris makes a nice drive and has a step on Semi Ojeleye as he gets into the paint. Al Horford helps off his man and is in perfect position to cut Harris off. Despite this, Morris helps off his man in the corner and does nothing to slow down Harris here. Instead, he is distracted as his man (Simmons) picks off Jaylen Brown, which frees Jimmy Butler for a wide open corner 3. A few Celtics (Tatum, Irving) have a bad habit of overhelping) and Morris is the most egregious defender.



3:00 remaining: Celtics lead 108-107

Transition defense has been an issue for weeks now with Boston and a lack of communication/awareness makes it easy to see why here. The Celtics are back in this instance but Morris is away from his usual man (Simmons) who is bringing up the ball. He starts to leave the man he is closest to (Harris) but that’s a bad idea for such a dangerous offensive weapon with no one nearby to pick him up. Simmons takes advantage by finding Harris in the corner, who burns a recovering Morris. The drive creates an easy 2-on-1, which leads to a dunk for Embiid. Morris makes this happening by leaving a guy in transition when he should have stayed home. This happens a lot with him, which has contributed to Boston's 29th ranked transition defense since the All-Star Break.



1:54 remaining: Tie game at 111

This one isn’t completely on Morris. Irving and Tatum make a bad gamble, doubling Butler, which leaves Harris a free lane to the rim. However, Morris is clearly the only help defender at the rim and he doesn’t have to worry about staying home with a shooter since he’s guarding Simmons. However, the free-agent-to-be is slow to react and has no chance of contesting Harris after Butler hit him with the pass. Good defensive teams would contest this shot and force Philly to make the extra pass as they try to recover. Bad ones give up the uncontested layup.



1:07 remaining: Tie game at 113

Morris is once again matched up with Simmons. Everyone in the world knows the one way Simmons can hurt you is by getting to the rim. He is not a threat to shoot. Yet, Morris remains pretty close to him at the top of the key and leaves himself vulnerable to a screen from Harris. This one isn’t all on Morris (Irving should have given him help here) but Morris can’t let himself get screened like that. He was too slow in this instance and fouled Simmons on what ultimately proved to be the game-winner. The Celtics didn’t allow shots like this in last year’s postseason, but it’s happened far too often on Wednesday night.



30 seconds remaining: Sixers lead 116-113

This column is supposed to be about the defense but I can’t help myself here. Embiid makes a nice block of Irving in the paint and Morris corrals the ball for an offensive rebound with a heads up play. With the Celtics trailing by three and five Sixers in the paint, this seems like a prime opportunity for a kickout 3 to tie the game to any of the three (!) open Celtics on the perimeter. Instead, Morris settled for a fadeaway jumper that misses.



So what’s the solution to these defensive woes?

This is the concerning part of the situation as another tough night of Morris takes shape. The Celtics really don’t have many options to take Morris minutes, especially with Baynes going down with a sprained ankle on Wednesday night. Stevens doesn’t trust Baynes in late game situations anyway, since he likes to rely on defensive versatility and switching to get stops.

“I think, ultimately, if you can’t get stops when you need to get stops, you won’t live very long in the playoffs,” Stevens told reporters. “It’s hard because the offenses are so good. If you can’t really dig deep and get stops and have some versatility defensively, you can’t last long. We need to show ourselves better in that regard.”

This is where the presence of Gordon Hayward and Brown are going to loom very large in the coming weeks. Both guys don’t have the size that Morris does but have been far superior defenders for the past two months. The more we see of Morris in crunch time, the more clear it is that he has too many lapses to be trusted with the game on the line. Even Ojeleye is a better option at points, especially on nights when Morris isn’t bringing anything on the offensive end.

It wasn’t all bad for Boston on Wednesday night. They got good offensive looks down the stretch that just didn’t go down. If Smart doesn’t make a selfish move, they probably win this game too. However, for the Celtics to piece their way throughout the postseason and make a run, they need to regain their elite defensive form and that starts with having the right personnel on the floor. Less of Morris, especially in crunch time, would seem to be a strong step in the right direction.