Run defense among top concerns for Colorado Buffs

Sep. 25—For all the issues plaguing the Colorado football team — and the list is long — among the most concerning is the way opposing running backs are slicing through the Buffaloes' defense.

UCLA's Zach Charbonnet became the latest opponent to enjoy a big day against the Buffaloes' porous defense, racking up 104 yards and three touchdowns on only nine carries in the Bruins' 45-17 rout of CU on Saturday at Folsom Field.

Four weeks into the season, no team in the country is worse at stopping the run than the Buffs (0-4, 0-1 Pac-12), who are allowing 323.25 yards per game on the ground and 6.95 yards per carry.

The Buffs' front seven — defensive line and linebackers — were expected to be the strength of the team, but they haven't been to this point.

"We're really working hard on trying to get those things shored up," CU head coach Karl Dorrell said. "Some of it has just been some of our players are in the wrong gap, they're not in their proper gap on that particular call. That's the challenging part, particularly if they're busting through there untouched, somebody's in the wrong gap.

"That's a big issue right now that we need to shore up more than anything, in my opinion."

The Buffs will visit Arizona (2-2, 0-1) on Saturday night in Tucson, Ariz. (7:30 p.m. MT, Pac-12 Network).

Arizona isn't nearly as dangerous on the ground as the Buffs' first four opponents, all of which rank top 21 nationally in rushing — including Air Force and Minnesota, who are the top two rushing teams in the country.

The Wildcats are 103rd in the country with 125.5 yards per game, but CU hasn't proven it can stop anyone yet.

In addition to Charbonnet, Minnesota's Mohamed Ibrahim (202 yards, three TDs) and Air Force's Brad Roberts (174, three TDs) had huge days against the Buffs.

Several backups have enjoyed success, too, as 14 players (including two TCU quarterbacks) have rushed for at least 40 yards against the CU defense.

Arizona has a trio of backs — Michael Wiley, DJ Williams and Jonah Coleman — who have been relatively effective this season.

"The biggest thing is the want-to," safety Trevor Woods said. "Guys gotta stick in their gaps. Guys have got to make tackles. I mean, that's our biggest problem right now."

According to Pro Football Focus, CU has had more missed tackles on run plays (41) than anyone in the Pac-12. Arizona State has had 40, but seven teams have 20 or less.

"For us defensively, definitely tackling and consistency (are the main issues)," linebacker Josh Chandler-Semedo said. "Like, we'll fit stuff up great at times and then we'll be nowhere near where we need to be. We'll tackle great at times and then we'll be looking like a backyard banjo or something like that."

Dorrell often points to youth when explaining CU's struggles, but that's not the case in the front seven. Eleven players in the front seven have at least 70 snaps played and eight are seniors, while two others are fourth or fifth-year juniors.

"We have veteran guys, we have older guys," said Chandler-Semedo, a transfer from West Virginia who led the Mountaineers in tackles a year ago. "We do have a lot of young guys, but the expectation is still high. It don't matter if you're a freshman or a senior out there; you're expected to play on the field. So that's the No. 1 thing for me is probably just tackling."

In addition to the missed tackles, CU hasn't been nearly as physical as its opponents, who have been able to move the Buffs and open running lanes.

"It's been a big concern since day one, since the TCU game," Dorrell said. "We've had a bunch of those big runs get out where we didn't even get in front of them. It's still plaguing us right now. We felt we had those things shored up (for UCLA). We did a couple of different defensive schemes for the game and they worked well, for the most part, but still we had some of those rushes that seemed like they're untouched and that's not good. It's not good and we have to get those things fixed."

Notable

CU has given up more runs of 20-plus yards (18) and 30-plus yards (11) than any team in the country. In 12 games last year, the Buffs gave up 19 runs of 20-plus yards and six of 30-plus yards. ... The Buffs opened as 16.5-point underdogs to Arizona. It's the first time in 14 games that Arizona has been a favorite. The Wildcats were underdogs in their previous 18 Pac-12 games and haven't been this big of a favorite against a conference opponent since they were favored by 21 against Oregon State on Nov. 11, 2017. ... This is the ninth time in the last 10 games that CU is a double-digit underdog, including all five games this year.