The Tampa Bay Lightning made a side deal with the Vegas Golden Knights prior to Wednesday's Expansion Draft to free up cap space and give the team more flexibility once free agency begins on July 1.

The Golden Knights selected Bolts defenseman Jason Garrison during the Expansion Draft. The Lightning also traded the negotiating rights to unsigned forward prospect Nikita Gusev, their second round pick in this weekend's NHL Draft and Pittsburgh's fourth round selection in the 2018 Draft (obtained in the trade that sent D Mark Streit to the Penguins at the trade deadline) to ensure the Golden Knights would take Garrison.

Following the announcement, Tampa Bay general manager Steve Yzerman said losing Garrison was difficult, but the Lightning are in a better place now salary cap-wise.

"We knew we were going to lose a player, and we felt like, taking everything into consideration, the salary cap, our short-term and long-term needs, our defense group, our forward group, we really felt that gives us the best option to free up cap space and gives us some flexibility to entertain other ideas and also we're giving younger (defensemen) an opportunity to play a significant role on our team."

Garrison was traded to Tampa Bay prior to the 2014-15 season and was an integral member of a Lightning team that won an Eastern Conference championship and advanced to the Stanley Cup Final that season. Garrison played 212 regular season games with the Lightning over three seasons, scoring 10 goals and adding 40 points. He will be entering his 10th season in the NHL when he joins the Golden Knights in 2017-18.

"He's been an excellent player for us, played a significant role on our blue line, a significant role in our top four and he's been a first class teammate and person in our community," Yzerman said. "We're really sad to see him leave because he's exactly the type of person and player we want to keep in our organization. We wish him good luck. We're grateful for everything he did for our organization. But again, our players all knew, we all have to lose a player. Nobody was really sure what was going to happen. We're disappointed we have to lose Jason. He's a really good man. He's been a great player for us and he's had good success in the three years he's been with us."

The Lightning have a handful of unrestricted free agents they'd like to re-sign this offseason, most notably Ondrej Palat and Tyler Johnson. After losing Garrison to Vegas in the Expansion Draft and dealing RFA Jonathan Drouin to Montreal for defenseman prospect Mikhail Sergachev last week, the Bolts are now in a better position to do so as well as make other moves with free agency looming.

"It gives us cap space to do some things," Yzerman said. "I can't guarantee what will get done, but it gives us cap space to do that. Our hope is to sign our upcoming RFAs, and that's our goal. But even signing those players, we need to still fill our roster and make our team as competitive as possible. So we need as much cap space as possible to do that."