But he refuses to be pushed into issuing a retained list because he insists decisions take time.
Player-of-the-year Jordi Gomez's year-long loan from Espanyol has now come to an end, as has Southampton winger Nathan Dyer's loan spell - two players Martinez wants to keep hold of permanently.
Top scorer Jason Scotland and defender Angel Rangel have been linked with moves away from the Liberty Stadium, while goalkeeper Dorus de Vries has yet to sign a new contract.
Decisions will also have to be made over some of the club's fringe players like Andrea Orlandi and Matty Collins who are out of contract, along with midfielder Owain Tudur Jones and defender Dennis Lawrence, who are both out on loan.
Martinez has also been linked with Queen of the South striker Stephen Dobbie, former Hearts winger Saulius Mikoliunas and Linfield goalkeeper Alan Mannus, but he is refusing to comment about any player until something is resolved either way.
If we lose players, it's going to be for the right reasons
Roberto Martinez
"Whenever anything is done in terms of signing contracts, I'll be the first one to tell our fans," said Martinez.
"I expect it to be a really busy summer, not for any reason I know of or not because I expect big numbers to go out and big numbers coming in.
"It is because you are looking at quality instead of quantity. We need to improve the present squad for next season and you really need to make good signings.
"Improving what we've got becomes harder every time in terms of characters and football talent. That's why I expect it to be really, really busy."
Swansea have been the surprise package in the Championship this season following their promotion from League One last year.
They have won many plaudits for their at-times dazzling football but Martinez believes his squad still can produce better.
"I think we've come a long, long way this season," he added.
"I don't think we've reached our peak with the players we've got. I think the squad has got a lot to offer.
"But it is true that we need to help the players we've got here to try to give us another dimension in certain things that we want to do different and that's why we need to bring the right personalities in.
"I'm just excited about the future and the new squad coming in but I'm looking back and I'm extremely proud of the players we've got in the dressing room now with what they've done this season.
"If we lose players, it's going to be for the right reasons and in football, there's not many times you can say that."
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