The Lightning announced Thursday morning that it has parted ways with associate coach Rick Bowness and assistant coach Brad Lauer.Bowness, who coached the defense for the past five seasons, was relieved of his duties.The contract of Lauer, 51, was up after this season and the two sides mutually agreed to part ways.General manager Steve Yzerman thanked both coaches for their service to the team, adding, "We appreciate all their knowledge and effort."Elliotte Friedman of Hockey Night in Canada tweeted late Wednesday night that Bowness was out.A bit of late-night coaching news: there is word Rick Bowness will not be returning to the TB bench. Bowness was a finalist for the ANA job in 2016 — and no doubt there will be interest.— Elliotte Friedman (@FriedgeHNIC) May 31, 2018It should not be a surprise that Yzerman decided to part ways with Bowness. Yzerman said the day after the Lightning was eliminated by Washington on the Eastern Conference final that the team's defense was not "quite good enough," both during the regular season and the playoffs, in 5-on-5 and on the penalty kill."So as a team we have to collectively improve defensively to be rock solid and to be able to be in these situations where we can shut a team out in Game 6 or 7. We're not quite there," Yzerman said.Bowness, 63, has coached the defense for the past five seasons. He has been a head coach for five NHL teams: Jets, Bruins, Senators, Islanders and Coyotes.Yzerman was asked about the coaching staff during the season-ending news conference. He said the staff worked hard and the team showed improvement, but continued, "I think some of the things that were working, the 5-on-5 needs to be better. Statistically it doesn't look great, but I think we were better. In the playoffs against some really good power plays at times, we looked like we were going in the right direction, so we continue to work, and we continue to get better, but this coaching staff works hard. I like the way our team plays. We still got to figure some things out."The Lightning allowed 230 goals during the regular season, which ranked 13th out of 31 teams. The 2.85-goals allowed per game during the regular season improved slightly to 2.82 during the 17 postseason games.It allowed 32.7 shots on goal per game during the regular season, which was 23rd in the NHL.