Stadium: Court 8 Round: 25 Ground: Clay
| UTR Pro Tennis Series Barcelona | 2021/08/06 08:30 | Jordi Munoz-Abreu v Alejandro Mendoza | 4-6,3-6 |
| UTR Pro Tennis Series Barcelona | 2021/08/05 07:00 | Francois Musitelli v Alejandro Mendoza | 6-3,5-2 |
| UTR Pro Tennis Series Barcelona | 2021/08/03 11:30 | Jaume Pla Malfeito v Alejandro Mendoza | 7-6,2-6,6-7 |
| UTR Pro Tennis Series Barcelona | 2021/08/02 08:30 | Alejandro Mendoza v Adria Soriano Barrera | 3-6,2-6 |
| Challenger Segovia | 2021/07/25 15:20 | Carlos Gimeno Valero v Alejandro Mendoza | 6-1,6-1 |
| Challenger Pozoblanco | 2021/07/18 16:35 | Emilio Nava v Alejandro Mendoza | 6-2,6-3 |
| Challenger Todi | 2021/07/11 08:00 | Giovanni Fonio v Alejandro Mendoza | 6-1,6-1 |
| UTR Pro Tennis Series Copenhagen | 2021/06/16 08:00 | Alejandro Mendoza v Daniel De Jonge | 1-6,2-6 |