Harrison, 23, was injured outside a Cleveland nightclub on Sunday night while the Ravens were on their bye, according to police.
A third-round pick in 2020, Harrison is scheduled to return to Baltimore on Monday after receiving medical care at a Cleveland hospital.
"I don't think it's severe at all," Ravens coach John Harbaugh said Monday. "I'm optimistic that it's going to be OK.
"Happy that he's OK and very grateful that he's OK and not hurt worse. Anything can happen. It's just a tough situation."
Harrison posted a note on social media to thank everyone who had reached out to him and the medical staff who treated him.
"Although today has been very overwhelming, I'm excited to get back on the football field very soon, playing the game I love to play," Harrison wrote.
According to a Cleveland police report obtained by The Associated Press, Harrison told officers, who were arresting four men involved in a shooting, that he was at a downtown club Sunday night when a fight broke out.
Harrison told police that security kicked people out of the club and that he was outside with a group when they spotted someone with a firearm. Harrison said everyone began running and he heard shots fired. Some details of the incident, as well as Harrison's medical information, are redacted in the report.
Harrison started the first five games of the season, but his playing time has significantly decreased recently. With veteran Josh Bynes getting more work at middle linebacker, Harrison has been on the field for fewer than 20 defensive snaps in the past three games.
Known as a thumper inside, Harrison ranks ninth on the Ravens with 22 tackles.
The Ravens (5-2) lead the AFC North and host the Minnesota Vikings (3-4) on Sunday.
Information from The Associated Press was used in this story.