Manchester United manager Louis van Gaal could still sign a centre-back, and even a striker, before the transfer window closes.
United have been linked to Real Madrid defender Sergio Ramos throughout the close-season, while a "surprise" striker had also been expected, although Pedro looks set to arrive from Barcelona.
"We have three [right-sided] centre-backs," Van Gaal said.
"We have Smalling, Jones and McNair but if he is much better than them then it is possible. We go for the best players and it has to be possible.
"[The injury to Jones] was very peculiar because he had the whole week tightness in his calf and he kept training but we have a very good doctor I think because this doctor discovered a minor thrombosis.
"We don't take the risk so we go to a second opinion to a specialist in the hospital and that was yesterday.
"That was after my press conference so I couldn't say anything. A specialist has said we have a new medical treatment and we have to keep him out for three weeks and we have to watch him."
Adding a striker before the window closes on September 1 is also a possibility, but not among Van Gaal's priorities.
"That is not a special item for me, it is more in the media they are discussing about a striker," Van Gaal said.
"The striker is Wayne Rooney and we also have [Javier] Hernandez, [Adnan] Januzaj and [James] Wilson. It is not a special objective for me.
"But when we can buy another striker who has a lot of qualities, more than our players, then we buy. But we have always done that."
