When he walked into the press room after the Massachusetts men’s basketball team’s exhibition game against Westfield State on Tuesday, the first words out of coach Matt McCall’s mouth were defensive concerns.

“I was really, really disappointed in us defensively, especially in the first half,” McCall said. “I thought we were way too consumed with offense. I thought we got too consumed offensively to where we didn’t guard. That was the disappointing piece… we kept getting whipped off the bounce, we’ve got to get back to guarding one on one and guarding the ball and pushing back and not getting whipped off the bounce.”

As a result, the focus in practice over the last few days, as the Minutemen prepare to host UMass Lowell in Tuesday’s opener, has shifted to the defensive side of the ball.

“I’ve really just been trying to tighten some things up defensively,” McCall said after practice Friday. “It’s really just been more of a defensive focus, trying to clarify some things. I think there’s some confusion at times out there on the floor for our guys defensively on when do we switch, when do we not switch, what do we do when the ball’s in the middle of the floor with the pick and roll, what do we do when the ball’s on the wing with the pick and roll, what do we do when the guy throws the ball ahead — really trying to clarify all those things for them so there’s no confusion.”

UMass came out man-to-man on Tuesday and stuck to that strategy for the entire night, switching more frequently than they did last season. Aside from whoever was at center — usually Sy Chatman — the rest of the Minutemen were switching just about everything, and the results were mixed. McCall, however, sees the issue lying at an effort level.

“I just think we lacked urgency,” McCall said. “I think our focus was on the other end of the floor and we were completely consumed offensively. We really lacked some urgency defensively, guarding the ball, we were getting whipped off the bounce too easily, when we were switching they were going around our guys, so I just thought it really boiled down to a lack of urgency, and being too consumed on the offensive end.”

Though McCall was disappointed with his team’s defensive performance, a few new faces flashed potential on that end. Keon Clergeot and Tre Wood showed real energy at the point guard spot and could give several of the Atlantic 10’s top guards issues on the perimeter. Samba Diallo and Jonathan Laurent both bring versatility and length to guard all five positions, and Sy Chatman had some highlight-reel blocks, including an emphatic swatting of Owl guard Jauch Green Jr.

NOT in Sy Chatman’s house! ???#Flagship ? pic.twitter.com/VK9Jrm0ztT

— UMass Basketball (@UMassBasketball) October 31, 2018

“I think [Diallo] and [Laurent] need to guard like guards. When they’re at the power forward spot, they need to defend like guards, and we’ll be able to switch and that’ll be our package,” McCall added.

The biggest problem on Tuesday was rim protection, as the Minutemen were outscored 42-36 in the paint, with 70 percent of Westfield State’s points coming in the paint. McCall’s not wildly concerned about paint defense either, considering Rashaan Holloway is expected to make his Mullins return on Tuesday.

“Defensively [Holloway] can take up a lot of space,” McCall said. “He’s gotten better at guarding pick and rolls since I’ve been here, he knows what to call, he knows what coverage to get into, so we’ve got to continue to get him better at that, but you have to account for him at all times.”

McCall said it’d been a good couple days of practice, seeing his guys better understand and become more comfortable with the team’s defensive principles. Despite a subpar defensive performance on Tuesday, McCall remains highly optimistic about his team’s potential on that end of the floor.

“In my opinion, with the personnel that we have, with the athleticism, with our length, there’s no reason we can’t be a top-50 defensive team in the country with our numbers,” McCall said. “But again, it’s gonna take some time, it’s gonna take some reps, but it starts with your urgency.

“I think we were too offensively consumed, and when you shift your focus from offense to defense, naturally we’ll become a better defensive team. It’s not what we’re doing, it’s not schematically — it works, we’ve just got to get better at it.”

UMass opens the 2018-19 season at home against the River Hawks on Tuesday.

Amin Touri can be reached at [email protected], and followed on Twitter @Amin_Touri.