BUFFALO, N.Y. — Jarmo Kekäläinen saw this summer coming. When he joined the Buffalo Sabres as a senior adviser last summer, the staff walked him through each player, how they were acquired and where they fit into the roster build. He then had a front-row seat to the team’s initial negotiations with Alex Tuch and Bowen Byram last offseason.So when Kekäläinen stepped into the general manager position in December, he knew there was a gap between the Sabres and Tuch in negotiations. And he knew Byram was unwilling to extend long-term because of his desire to be a No. 1 defenseman. So while the Sabres were going on a second-half run for the ages and made the playoffs for the first time in 15 years, Kekäläinen knew change was coming. In both cases, he tried to convince the players to change their minds, but he knew he needed to have a plan for life without Tuch and Byram.“Basically, we thought about it every day since last offseason,” Kekäläinen told The Athletic in a sit-down interview following free agency.July 1 was not a busy day for the Sabres, and that was by design. Buffalo has 14 forwards on the roster with RFA Peyton Krebs still to sign. The Sabres also have seven defensemen and three goalies under contract. Any free-agent signing would have necessitated a trade to move somebody else off the roster. Kekäläinen feels the Sabres addressed Byram’s departure by adding Olen Zellweger and Louis Crevier, who will both compete for top-four minutes. From the beginning, Kekäläinen has been comfortable with the internal options to replace Tuch. Zach Benson, Josh Doan, Jack Quinn, Konsta Helenius, Noah Östlund and Jiri Kulich all have room to grow and replace some of Tuch’s production.NHL free agency: Early winners and losersShayna Goldman and Madison EadesBut beyond that, Kekäläinen is thinking about the Sabres’ competitive window. They were a goal away from reaching the Eastern Conference final. Tage Thompson is 28 and has four years left on a bargain contract. The rest of the Sabres’ core players are 26 and younger. They were one of the youngest teams in the NHL. So the balancing act is capitalizing in the short-term without compromising what could be a long competitive window.“That’s what we think about all the time,” Kekäläinen said. “Even referring back to the Tuch situation, we’re watching Östlund, Helenius, Jack Quinn, Doan, Benson, all of those guys. How are they coming along in their career? How are they developing? What kind of role can they take a year from now, two years from now? I’d say our window is open right now, and I think it’s only going to get wider. That’s how I would put it. You look at the teams that were in the Stanley Cup; it doesn’t happen like this where the window opens, and first year you win. It usually happens where you learn from experience, like we did this year. We won the first round, went to Game 7, one shot away from being in the conference final. That’s a valuable experience. Now, how do we get to the next level? Carolina, for example. How many times were they disappointed before they finally got over the hump?”