"There's nothing like playoff hockey," O'Reilly said. "It's what we all kind of dream of doing. Unfortunately in my career, I haven't done it enough. I plan to come in and help this team get there and help this team win. Last year, they were one win from getting in. With the playoffs now, all you have to do is get in and you have a chance at winning the Cup. This team was so close."
Buffalo received forwards Patrik Berglund, Vladimir Sobotka and Tage Thompson, a first-round pick in the 2019 NHL Draft, and a second-round pick in the 2021 NHL Draft.
O'Reilly is hoping to help the Blues power play, which was 30th in the 31-team NHL (15.4 percent). He scored 15 power-play goals (tied for third in the League) and 23 power-play points last season.
"I think the last couple of years, I've had success out there on it," he said. "I think Buffalo, we've had some good power plays over the past few years and I plan to bring that over and hopefully be a key factor."
O'Reilly said he wished for better results with the Sabres.
"With the trade, it's disappointing to see that I wasn't a guy or a piece that could help, but I'm more excited that there's another team that wants me," he said. "I get a chance to go to a great city and a great team and a team that's got a ton of good pieces and they are trying to win right now and that's something I really want to be a part of.
"I love that city and I love those guys on that team, but we just didn't get the job done."