"I don't think one's any further in front than the other,'' he said. "I think they've both done a good job. As far as these five practices, usually one day one guy is ahead of the other and the next day the other guy does the better job."
"Hopefully as these preseason games go, as these practices go, I hope one of them will make the decision easy on us. One of them will just take off and start playing really well and usually the answer becomes really easy."
Hoyer has been taking first-team reps in workouts, but Shanahan said Manziel soon will work with the first team.
Head coach Mike Pettine said Thursday that it's a "knee-jerk reaction" to believe Hoyer will be the Week 1 starter because he's currently taking reps with the first team.
Hoyer, 28, threw for 615 yards, five touchdowns and three interceptions over three starts with the Browns last season.
Cleveland selected Manziel with the No. 22 pick in this year's draft. The 21-year-old won the Heisman Trophy in his redshirt freshman season at Texas A&M.
Addressing media Friday about his off-field behavior, Manziel said he has made some "rookie mistakes."
The Browns went 4-12 and finished in last place in the AFC North last season.
- Chris Johnson