"We have to work on our alignments on defense, figure out the run game and improve our pass coverage," he said. "In general, we've got to get a lot better."
Utah's defense had trouble containing USU quarterback Chuckie Keeton, who was 31-for-40 for 314 yards against the Utes.
The good news is after a poor start, Utah's defense did improve, holding the Aggies to 186 yards in the second half after giving up 301 in the first half.
"The corners took some lumps but it wasn't all their fault," Whittingham said. "We had some problems under coverage with the linebackers, and the pass rush was not good enough. There are a lot of things we have to improve defensively if we are going to be successful this year."
The Utes knew inexperience was going to be an issue this season, a problem magnified by the absence of Brian Blechen, the senior whose year is in jeopardy due to tendinitis in his knees.
"Utah State did a great job of getting the defense disoriented with tempo and formation shifts, and you have to give Chuckie Keeton credit," Whittingham said. "But the pass coverage was shoddy at best; we need to get better."
Offensively, Whittingham wants to see more out of Utah's tight ends, particularly with receiver Kenneth Scott out for the year with a lower leg injury.
Jake Murphy had two catches for 41 yards and a touchdown, and Westlee Tonga had none.
"We have to have more production there," Whittingham said. "The tight ends didn't make as much of an impact as I thought, and partially that is our fault as coaches, especially with Scottie out. That is something we have to take a look at."
The Utes have a busy week ahead, with less concern about Weber State than themselves.
"They say you make your biggest improvements from Game 1 to Game 2," Whittingham said. "We're hoping that is applicable to us this year. We have to keep working; there are no shortcuts or magic solutions."
Weber State at Utah
P Saturday, noon
TV • Pac-12 Networks