Fairchild, 21, was released from the Washington County Jail at 12:19 a.m. Tuesday after posting a $1,500 bond. Petrino handed down his punishment only a few hours later.
Petrino didn't speak with reporters during Arkansas' Pro Day on Tuesday morning. But he addressed Fairchild's suspension in a statement released through the university later in the day.
"Freddie Fairchild has been suspended from our football team pending a review of a violation of team rules," Petrino said in the statement. "He will not be allowed to participate in any team activities during the suspension.
"We will allow the legal process to take its course on this matter, and Freddie will be provided the appropriate support during this time."
According to a Fayetteville police report, Fairchild was arrested after he allegedly attacked a woman he has had a relationship with for more than a year.
"Between midnight and two-thirty this morning (Monday), Fairchild physically attacked (the) victim, causing injuries to her head, face, extremities and pelvis," the report said. "(The) victim was afraid he would hurt her worse during this time, and she reported that he would not allow her to leave for several hours."
Fairchild was arrested Monday afternoon and booked into the Washington County Jail at 6:11 p.m. on charges of third-degree battery and false imprisonment.
He declined to give a statement to police about the incident, according to the police report. His future with the Razorbacks, meanwhile, remains uncertain following his arrest.
Fairchild, who started 11 games as a sophomore last season, is the first player to be disciplined by Petrino since he was hired Dec. 11 to replace Houston Nutt.
Fairchild, a Little Rock native, returned from a torn anterior cruciate ligament in 2006 to lead the Razorbacks with 4 1/2 sacks last season. He also ranked third on the team with 92 tackles.
Arkansas opens spring practice April 3, and at 6-foot-4, 225 pounds, Fairchild was expected to be one of the team's defensive leaders.
He's a returning starter on a defense that lost several key players from last season to graduation, including starting middle linebacker Weston Dacus.
Petrino didn't indicate in his statement if Fairchild would be suspended for any games next season or if the possibility of getting kicked off the team existed.
"The Razorback football program is committed to a high standard of conduct," Petrino said in the statement, "and our student-athletes are expected to adhere to that standard on and off the field."
Fairchild Suspended Indefinitely
Hawgs Daily Top Stories
Scout 2017 Rankings DirectoryThe Scout positional, state, regional, national and team rankings for the Class of 2017...
2017 Signing Day announcement scheduleComplete list of announcement times for the most high-profile uncommitted recruits in 2017.
Scout's Top 25 Recruiting ClassesA look at Scout's top 25 classes with just over a week to go to Signing Day.
Weekend Official Visit PrimerScout takes a look at the biggest visitors for the upcoming weekend in the Power 5 conferences...