Petra Marcinko of Croatia enters the Oeiras semi-finals as the higher-ranked player at world No. 80, seeking to extend a promising run on clay. The 26-year-old has won three of her last five matches, including straight-set victories over Greet Minnen and Natalija Brancaccio, though she suffered a straight-set loss to Tereza Kostovic in her most recent outing. Marcinko holds no prior head-to-head record against opponent Susa Kraus, making this a fresh matchup in the semi-finals. At Pinnacle odds of 1.87, she is favoured to progress to the final.

Susa Kraus of Austria arrives at the Oeiras semi-finals ranked No. 120, having navigated a mixed recent form sheet with two losses in her last five matches. The Austrian claimed notable wins over Wimbledon junior champion Whitney Osuigwe and Olga Selekhmeteva in straight sets, demonstrating her capability on the surface despite consecutive defeats to Sorana Cirstea and Amanda Parks. Playing her first semi-final clash with Marcinko, Kraus is available at Pinnacle odds of 1.98 as the underdog in this clay-court encounter.