"I would say if I was sitting in his [Solskjaer's] shoes I would be very frustrated," Ferdinand told BT Sport.
"I said earlier I was filled with optimism at the end of last season. Got the team into Europe, the Champions League, which I'm sure would have been part of what was on the tin to do.
"But I feel in terms of acquisitions in the transfer market he'll be frustrated because he hasn't got what he wanted.
"I don't feel that whatever they've got in this window has improved the first 11. That's the problem."