Olympiacos signed Zinedin Smajlović, a 22-year-old Swedish and Bosnia-Herzegovinian central defender, from the Norwegian club Sandefjord. The total transfer cost is €6.5 million, comprising a €5 million fee and €1.5 million in bonuses. Smajlović, who has 3 caps for the Sweden U21 team, signed a four-year contract that includes an option for an extra year. Smajlović joined Sandefjord in February 2025 and made 36 appearances in the Eliteserien, during which he scored 2 goals and provided 3 assists. This transfer is Olympiacos's most expensive of the summer to date. The club signed him ahead of competition from Feyenoord, Marseille, Celtic, Rangers, Toulouse, Bodø/Glimt, and Brann. Prior to the agreement, Sandefjord's asking price was reported to be between €5,000,000 and €6,000,000. Both Olympiacos and Celtic had previous bids for the player rejected. According to Transfermarkt, the player's current market value is €3.00m.