Arsenal hero Martin Keown has questioned Manchester United's swoop for Marcos Rojo.
The defender signed for United this week from Sporting CP.
Keown told the Daily Mail: "I saw a bit of him at the World Cup and he looked a tidy player, but I still find it a strange situation at United.
"First Patrice Evra signs a new contract at the end of the season and seemingly thinks he's ready to stay another year, then he is sold to Juventus. Then the club spend the best part of £50m on essentially two left backs in Shaw and Rojo, but are still looking to play with three central defenders and wing backs.
"It looks likely that Rojo will slot in as one of the back three on that left side, but you can buy as many players as you like - if their roles and responsibilities are not defined than they're not going to be much use. We saw that in the first half against Swansea - nobody looked like they knew what their role was.
"He seems to have a bit of a fiery reputation, too, but I think the manager will tell him what's required and try to curb that. You want people with a bit of an edge and who are aggressive but he's coming to an age now where he has to mature and that side of his game will calm down I'm sure."
