Texas Tech dismissed defensive coordinator Matt Wallerstedt after he was suspected of being in the school's football building while under the influence of an unknown substance, sources told ESPN.com.
Wallerstedt was sent home from the team facility on Monday, according to ESPN's source. CoachingSearch.com first reported Wallerstedt's dismissal on Thursday.
ESPN's Jake Trotter has more on Wallerstedt's potential replacement:
"Wallerstedt is expected to be replaced by co-defensive coordinator and linebackers coach Mike Smith, who played for the Red Raiders and graduated from Texas Tech in 2004."