What happened: Major League Soccer activated its summer transfer window on Tuesday, enabling clubs across the league to formally add midseason acquisitions to their active rosters. The registration window clears several high-profile arrivals for match action, highlighted by Antoine Griezmann joining Orlando City SC and Robert Lewandowski moving to Chicago Fire FC. Meanwhile, Charlotte FC completed its three-year Designated Player deal for Allan Saint-Maximin, as Inter Miami CF works to finalize an unannounced acquisition of midfielder Casemiro.

Why it matters: The midseason registration period allows front offices to reshape their senior rosters ahead of the final stretch of the 2026 regular season. Integrating veteran European additions into Designated Player and international roster slots immediately alters rotation depth during a congested summer match calendar. For clubs hovering near the postseason cut line, incorporating reinforcements right at the opening of the window maximizes their availability for crucial conference fixtures.

What to watch: Clubs across the league will finalize international transfer certificates and visa paperwork to clear new signings for upcoming weekend fixtures. Inter Miami CF is expected to formally announce terms for Casemiro following his registration.