Natus Vincere’s CS:GO captain Kirill “⁠Boombl4⁠” Mikhailov has tested positive for COVID-19 ahead of his team’s debut in ESL Pro League season 15 and will miss the start of the action in Group D, the organization announced today.

The CIS powerhouse will use Daniil “⁠headtr1ck⁠” Valitov, a 17-year-old from NAVI Junior, during Boombl4’s absence. The Ukrainian youngster had to catch a last-minute flight to Düsseldorf, Germany, where the competition is being held, and will play the matches isolated from his teammates as a result of the travel, according to NAVI.

The loss of Boombl4 comes as a blow to NAVI. The PGL Stockholm Major champions have been going through a lot since Feb. 24, when Russia invaded Ukraine. The team has three Russian players, three Ukrainian players, and a Ukrainian coach. They fell to G2 in the semifinals of IEM Katowice on Feb. 26 and have not played an official match since then.

This is the second time Boombl4 has tested positive for COVID-19 in less than two months. The Russian in-game leader had to play some IEM Katowice group stage matches isolated from his teammates because of the positive result. He can’t do that now in the ESL Pro League because he tested positive ahead of his flight to Germany.

NAVI will face AGO tomorrow at 5:30am CT in the ESL Pro League season 15 Group D opener. The rest of the group is composed of Heroic, Astralis, Evil Geniuses, and Complexity.