This is the big hole in the team. I still rate Joao Moutinho but two things are undeniable about him: 1. He's injured a lot and 2. He wasn't the same player after his injury. If he can get close to his 2020 form, then Orlando are set at starting left back, but even if Moutinho can reach that level again, depth is desperately needed.
Kyle Smith is the only real backup left back, and he's a right-sided player who is limited offensively and also important cover at right back. There's also Mikey Halliday, but he's also more of a right back and still an unfinished prospect. Emmanuel Mas provided decent cover down the stretch last season, but he wasn't brought back.
There is talk that draft pick Nathan Dossantos could potentially play left back, but relying on a rookie center back at left back is far from ideal. If there's one more move Orlando City makes before the season starts, I hope it's here.