Frustrated Lisandro Martinez rues Manchester United's missed chances in West Ham loss
The Argentina international, who joined in 2022, rued the chances United missed in the first half, with Alejandro Garnacho hitting the crossbar and Lukasz Fabianski's diving save denying Casemiro.
"Today we played very well in the first half, but in the second half we dropped (our level)," Martinez told MUTV.
"I hate to lose and I hated losing that (game) and in this club, it is not what we want."
United have only three wins in the league as they sit 14th with 11 points.
"I am so frustrated honestly... we miss (so) many chances and it is difficult to accept it, but we have to. That is it," the defender added.
"We'll give everything to put this club where it deserves (to be)."
United will host Chelsea in their next league game on Sunday, after Wednesday's League Cup clash with Leicester City.