Everton this week dismissed a B£28million offer for the highly-rated pair from Old Trafford as "derisory and insulting".
It remains to be seen whether United, now managed by former Toffees boss David Moyes, make an improved bid but Martinez says it would not be welcomed.
The Spaniard said: "There is no temptation. In football you want to keep your best performers and that is where we are.
"You always get into a debate when there is a club that matches the valuation of a player. Then you need to make a decision.
"That has never been the case and where we are is we want to keep out most influential players and build from that.
"It has been well reported what the approach has been. We take it as a football compliment and move on. Now the focus has to be the games."
Several managers in the Barclays Premier League have expressed their frustration that the summer transfer window remains open after the start of the season.
There have been calls for it to close before the first game but that would not mirror the situation in other European leagues.
Newcastle boss Alan Pardew was particularly angry after Arsenal submitted a bid for his player Yohan Cabaye hours before Monday's game at Manchester City.
Chelsea's Jose Mourinho and Swansea's Michael Laudrup have also said the transfer period should conclude earlier, as well as Martinez.
Martinez said: "I have said it time after time, it is time for the football authorities to look into the situation.
"I think the window is getting out of hand and really affecting the values of the league and the human side of the players in a very unfair manner.
"It is about time we stopped the window or the official games in the middle of the window."
- Sports & Recreation
- David Moyes