The NHL collective bargaining agreement gives players the ability to enter unrestricted free agency if they remain unsigned four years after their draft, a situation that transpired with now New York Rangers forward Jimmy Vesey last summer. The Sabres drafted Petersen in the fifth round in 2013.
Still, Botterill said he remains a strong proponent of drafting players from the NCAA.
"It's always a possibility, but I still believe a lot in the college model and having players develop there," Botterill said. "I think it's a great scenario. It's very good form a standpoint of the work ethic, the strength training, juts the pace of play for skaters.
"Overall, I think you still want to get the best player, you've got to work on developing that relationship with your development staff over time and when it comes to signing, hopefully they feel proud and want to be a part of your organization."
Speaking of goalies, Botterill confirmed that Linus Ullmark was among the players protected by the sixth-round pick that was sent to Vegas along with William Carrier during the NHL Expansion Draft on Wednesday night.
After playing 20 games for the Sabres during his rookie season in 2015-16, Ullmark was a workhorse for Rochester last season. He posted a 2.87 goals-against average in 55 games and was rewarded with a two-year contract extension earlier this month.
"He was one of the players that we certainly wanted to keep from a depth perspective," Botterill said. "We wanted to strengthen our goaltending depth throughout the entire organization. He's a player that I have to continue to get familiar with but our staff here is very excited about him."