England left-back Baines was reportedly the subject of a bid from Manchester United a few weeks ago while Arsenal have been linked with Belgium midfielder Fellaini.
However, asked if there had been any recent bids for the pair, Martinez replied: "Not at all, not at all.
"I know that is not what you might want to hear but everyone here is focused on fighting for spots in the starting line-up and the competitive level in this group is impressive.
"I don't think speculation is healthy, we are just trying to become as good as we can before the transfer window closes.
"If we get clubs talking about our players we take it as compliment, because the players have been impressing and doing really well.
"We are in a great position financially and we want to start the season with the best squad we can."
Asked if he was surprised that United had not made an improved offer for Baines, Martinez added: "No, the last concern I have is what other clubs do.
"I can say I have been really impressed with the togetherness of this group. I can see that in training every day and it makes me proud."
Regarding whether he expects to have retained all his key personnel by the time the Premier League season gets under way, Martinez said: "You should never ask a manager that!
"The modern game does not allow a manager to have that control.
"But I'm very excited, the squad is very strong. We have some good youngsters who I feel can come in and help the first team.
"We will carry on trying to become as strong as we can."