Astralis, the Danish CS:GO powerhouse and the most dominant team over the past two years, surprised just about everyone when it added an additional player to its already full roster on March 22: Patrick “es3tag” Hansen from Heroic. He’ll join on July 1.

It’s an unusual move in CS:GO, but Astralis’ head coach Danny “zonic” Sørensen sees it as essential for the team’s performance over long stretches of time. “The reason why we have done this is health and long term performance,” Zonic told Dot Esports.

Astralis has been considering a transition like this since device, one of its star players, suffered severe gastrointestinal issues in November 2017. Those health issues were related to the strain put on his body from an excessive travel schedule. Device missed three consecutive LAN tournaments after he started having issues at IEM Oakland and Astralis had to use temporary stand-in players.

A six-man roster has been a recurring point of discussion in CS:GO and Astralis is the first top-tier team to do so. The closest example to what the Danes have done is AGO, a Polish tier-three team that has seven players and wants to have two players for each role. Another example would be Immortals, whose Brazilian roster fell apart due to internal issues in 2017—even before the sixth player was officially signed.

Some of the bigger tournament organizers in CS:GO, such as ESL and BLAST Premier, allow substitutions between maps, but the Majors don’t. “We are not speculating in swapping players between maps, but on giving players some much needed breaks and time for recovery—mentally and physically,” zonic said. “That being said, we will work with the options, and I will certainly not say, it could not be the case on a later stage.”

Zonic, Astralis’ performance team, and the players all took part in the decision to add es3tag. According to zonic, the org chose es3tag because it knows him well and the 24-year-old understands Astralis’ culture and its approach to performance optimization on all levels.

“At the same time he is a very well versed all-round player with an extremely high base level,” zonic said. According to the head coach, es3tag will join the team on equal terms with the other players. “Initially it’s all about learning the ‘language’ of the team and getting used to how we play. Then we will focus on specifics later on.”

Although the decision was made by everyone involved in Astralis, it’s ultimately up to zonic and Kasper Hvidt, Astralis’ sports director, to decide who will play. Zonic trusts the process and doesn’t think that it’s right to compare what Astralis do to what other teams have tried in the past.

“I don’t think it has ever been implemented by an organization of our kind with the resources and structure around the team,” zonic said. “We believe this will ultimately help us improve the overall performance, we believe it is the healthy choice for the players that will extend their active careers and we believe it is the right decision.”