Manchester: Manchester United`s defensive woes deepened on Sunday with Argentine defender Marcos Rojo dislocating his shoulder and centre back Chris Smalling getting sent off in the 1-0 derby defeat by Manchester City.
Already missing the injured Jonny Evans and Phil Jones as well as left back Rafael, manager Louis van Gaal is struggling to put together a back four.
"Maybe I`ll know more tomorrow but I don`t think Rojo shall play against Crystal Palace next week," Van Gaal told the BBC.
"It is a disaster having so many defenders injured and every week you play with another defence."
United finished against champions City with midfielder Michael Carrick and winger Antonio Valencia pressed into defence along with 19-year-old substitute Paddy McNair and fellow teenager Luke Shaw.
Despite playing with 10 men after Smalling was recklessly sent off shortly before halftime, United held out against their local rivals until Sergio Aguero struck the winner just past the hour mark of a scrappy contest.
Van Gaal refused to blame the defensive disruptions for his side`s continued problems.
"We have very good players so I don`t cry for the injuries. It`s a pity, but it`s not an excuse," he said.
"When [Michael] Carrick and Paddy [McNair] came in we did fantastic. We can do it, but we have to score and today we didn`t score that`s why we don`t have one point or three."