"If he doesn't get out there soon, we just have to move past him," Whittingham said. "We have to. There is no other way, no other alternative."
Whittingham said the Utes could make a decision what to do next week.
"If guys still aren't out on the field we have move past them, that is just how it is," he said.
Blechen does have a redshirt year available, but his presence is needed now more than later.
He is the only senior among the linebackers on the depth chart and is one of the most experienced players on the team, having started since his freshman season.
His backup is projected to be Jacoby Hale, a junior who played in seven games last year before suffering a season-ending injury.
Other linebackers on the depth chart are junior V.J. Fehoko, sophomore LT Filiaga, sophomore Jared Norris and freshman Uaea Masina. Only Fehoko and Filiaga started games last year with Fehoko getting six starts and Filiaga starting two games.
If the linebackers were the only inexperienced group among the defenders, the Utes might be able to make up for the deficit with standout play in other areas. But given the depth and experience issues at corner and safety, the Utes' defense suddenly seems very suspect.
The good news out of Friday's morning session came from quarterback Travis Wilson, who said he is ready to go in Saturday's scrimmage.
He knows the pressure is on the passing game to perform better and said the Utes can improve.
"We have to make sure we are good on the timing and running the right routes," he said. "We've seen the mistakes on film and we definitely need to get them corrected."
Whittingham said the Utes will run through about 90 plays. Position battles that remain undecided are at backup quarterback, running back and corner.
The Utes ended their afternoon practice session early so players and coaches could attend services for former assistant Aaron Alford, who died of a heart attack on Monday.
Alford served as an assistant coach at Utah from 2007-2010 and also worked in administration as Utah's director of high school relations.
"He was a great guy, one of the genuinely great guys," Whittingham said Friday.
Whittingham noted the Utes have had to deal with a lot of tragedies this year. The week before camp began, incoming freshman Gaius Vaenuku died in a car accident. The Utes will wear a sticker with his No. 95 on their helmets this year to honor him.
"We've had a lot of things to overcome," Whittingham said. "That is part of life, but it doesn't make it any easier."
Alford was going to help coach Park City's high school team this year.
Passing game coordinator Aaron Roderick said Alford had just called him recently to go mountain biking.
"He was a great friend," he said. "A lot of kids in this program still love Alford and he did a lot for these players and was involved in their lives. He was a great guy."
Services for Alford will be held Saturday at 10 a.m. at Mountain Life Church in Park City.
What we learned • The Utes had a relatively light day so they could be fresh for Saturday's scrimmage.
What is ahead • Saturday's scrimmage is critical for deciding who will be the backup to quarterback Travis Wilson.
Who was missing • Linebacker Brian Blechen continues to be slowed by injuries.