He currently plays for Alianza FC San Salvador Women, wearing the number 4 shirt. At the international level, he represents El Salvador Women. He plays primarily as a Defender.

Throughout the CNCF WCC 2025-2026, L. Guillén featured in 4 matches, averaging 1.8 tackles, 0.8 interceptions, and 3.3 clearances per game, while blocking 0.3 shots per game.