‘The element of the O’Reilly trade that really sunk Botterill is a name who wasn’t involved in the deal at all: Casey Mittelstadt. He was the Sabres’ No. 1 prospect and had dipped his toes in for six NHL games at the end of 2017-18. He was the 2018 World Junior Championship MVP. Our Future Watch panel of active NHL scouts and team executives named him hockey’s No. 1 NHL-affiliated prospect that year. The O’Reilly trade was pretty clearly contingent on Mittelstadt being ready to step in as Buffalo’s No. 2 center behind Eichel. While it hurt as well that Berglund wasn’t around to help fill O’Reilly’s void as a checker, Mittelstadt obviously struggled. He ended up demoted to the AHL this season.’