Rosters are being submitted for the first qualifier for the EU Summer Regional, set to take place Wednesday. Many squads will be making changes and playing this first qualifier with unstable roster arrangements.

Here are some highlights taken from the ESL roster page for the event. Read on to see some of the major moves that have been uncovered so far.

Team Liquid: bkb trying out

In: Arturs "bkbgrnrjefek" Hlibovs

Out: Oskar "Jowe" Halamus

Liquid made headlines late last week when they dropped warrior Oskar "Jowe" Halamus. They didn't announce a replacement, but the team's roster on the ESL website shows that they plan to play with Arturs "bkbgrnrjefek" Hlibovs for the first qualifier.

bkb was a member of Virtus.pro during the Road to BlizzCon before that roster disbanded. More recently he played for Team Sandwich Monkeys, before returning to Virtus.Pro for the EU Regional at Heroes Championship Katowice.

Now, trying out for Liquid, bkb has the opportunity to play with a high-potential roster that could do some serious damage in the EU scene. Of all the moves on the roster page, this is perhaps the most exciting.

Natus Vincere: More changes

In: Marcin "Wolfz" Radzewicz, Ivan "Sportbilly" Koturić

Out: Martin "Crozzby" Rugh, Anthony "Danatan" Lossec​

Natus Vincere's disappointing 2-4 finish at Katowice basically guaranteed that changes would happen for this roster. Crozzby announced last Thursday that he had been released, but that seems to have been only the beginning.

In addition to dropping the former mYi player, Na`Vi appears to have parted ways with top ladder player Danatan, who is now listed on the roster for Evil Murkies.

Stepping into the open spot is Sportbilly, who has played both flex and support in the past. With support Fran "GranPkt" Núñez continuing on the roster, Sportbilly will likely step into the ranged assassin role. This is just the beginning for this new Natus Vincere roster, but the potential long-term addition of Sportbilly is a great sign.

Wolfz, Na`Vi's second pickup, most recently played with Team Sandwich Monkeys in the playoffs for Enter The Storm Cup #4.

Team Sandwich Monkeys: adrd and a new roster

In: Marc "ETFonTop" Wippich, Patrick "Pheilox" Riehle, Matic "Zarmony" Mikec, Lampi

Out: Everyone except Adrian "adrd" Wojcik

The old TSam squad disbanded, played a few tournaments anyways, and then finally, actually disbanded. Now, Adrian "adrd" Wojcik is back, with a new roster composed of three-fifths of Bubble Squad alongside competitive veteran Zarmony.

Bubble Squad made some progress, but were far from being a Top 4 team. Now, with the veteran guidance of adrd and Zarmony, this team could be a big contender in EU.

Virtus.pro: The shuffle continues

In: Łukasz "LeofromKorea" Mirek, Alexander "Remmerballer" Remmerswaal

Out: Arturs "bkbgrnrjefek" Hlibovs, Evgeny "Lunarn" Evdokimov

Virtus.pro has been trying to find a winning combination for their Heroes team for some time. The closest they've come was certainly at Katowice, where the roster that included bkb and Lunarn was able to fight its way out of groups, despite some tough opposition.

But they haven't retained either of those players, and they find themselves entering the Summer qualifier with a roster that has a lot of unknowns.

Leofromkorea, a former member of G2 Esports, certainly has deep competitive experience. Remmerballer, a former member of TCM-Gaming, has less high-level experience.

At first glance, this doesn't seem like the kind of roster that can catch fire — but neither did the roster that VP fielded at Katowice. VP remains a team that opponents should keep an eye on.

Josh "Gauntlet" Bury is a news editor for theScore esports. He is also a Warlock Car Salesman. You can follow him on Twitter.