Since the former Toffees boss succeeded Sir Alex Ferguson at Old Trafford, the Premier League champions have taken a different approach to player recruitment - publicly acknowledging bids for Cesc Fabregas and Everton duo Marouane Fellaini and Leighton Baines.
Martinez, whose club had branded the joint bid for the pair as "derisory and insulting", feels that a more private offer would have reaped more positive rewards - but he is not expecting United to return.
"I have never seen Manchester United working in this manner before," the Spaniard told reporters. "When you want a player you just do the business quietly, you get it done and that's it. I don't know if this is a new way of working at United.
"I don't expect a new bid. In fact, it wasn't even a bid because it never reached any sort of valuation of the players. There isn't an offer on the table where anyone would consider anything. If they'd matched the valuation maybe then you would listen to it but that hasn't been the situation."
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He continued: "If you invest a certain amount in a player and that player is one of the outstanding performers in the league, then I'm sure that price has gone up. It is common sense, isn't it?
"The market brings the valuation. There are aspects to consider, like the age of the player and the length of his contract, but then it is very easy to look at the current price of that type of player in the market. That gives you a valuation.
"But I am not trying to fix a price for a player. It would be wrong to say that. I don't want to sell. But what is clear is if you want to buy a player and he's been a good performer, you must offer a higher value than what the club invested to get him. That's common sense."
Martinez, though, praised the duo for continuing to perform in training and on the pitch, adding: "So far everyone has been in a great frame of mind. They are focused, they are top professionals, it is their job and at the end of the day it is their passion. You can imagine it is not a fair situation for anyone."