Casey Pachall left TCU for the rest of the fall semester and is checking into an unnamed inpatient rehabilitation facility, coach Gary Patterson announced Tuesday.
Pachall was suspended following his arrest early last Thursday morning for driving while intoxicated, his second such off-field matter in eight months. A failed drug test was made public in August, but Pachall did not face legal repercussions.
Pachall will likely enter a 30- or 60-day program, Patterson said.
"Hopefully, what our plan is that he (Pachall) gets himself right and keeps the door open for us as far as an opportunity for him to be able to come back here and enroll in the spring," Patterson said. "He would be able to graduate in two semesters, which is the ultimate goal for us."
Pachall, 21, was stopped near TCU's campus for running a stop sign and hitting a curb last week. He then registering a blood-alcohol level of more than .15 -- nearly twice the legal limit in Texas.
He has since been suspended indefinitely by Patterson. Pachall's parents, reached by CBS Sports last week, declined to comment on the suspension and said they were hoping for "whatever's best" for their son.
Pachall has been in trouble before. He shared a house with former TCU linebacker Tanner Brock, who was among four football players arrested during a February campus-wide drug bust. Pachall admitted drug use to police, but his only punishment, Patterson said, was to complete drug and alcohol counseling.
A junior, Pachall started all 13 games for the Horned Frogs last season. This season, he passed for 948 passing yards and 10 touchdowns for the 4-0 Horned Frogs. He ranks fifth nationally in pass efficiency.
He was replaced by redshirt freshman Trevone Boykin last week in a 37-23 loss to Iowa State that dropped TCU out of the Top 25 polls and snapped a 12-game winning streak. Boykin threw three interceptions in the loss. The Horned Frogs play four ranked Big 12 opponents in their next six games.