Gareth Barry recently agreed a permanent deal at Goodison Park following a successful loan spell last season, but Martinez has yet to make any further additions to his squad.
The Spaniard confirmed earlier this week that highly-rated Anderlecht forward David Henen was close to joining Everton and it appears other fresh faces can be expected.
Martinez told talkSPORT: "The main priority was to have continuity in what we did last season. We have had a few players signing extensions and we got Gareth Barry becoming a permanent signing, which was huge for us.
"In the next couple of days we will have a few players coming in because it was important for me to assess the youngsters.
"The youngsters have done terrific and are showing the good work we are doing in the academy at Finch Farm, but there are areas that need to be strengthened and over the next few days we are going to get the three, four players we need just to finalise the squad facing the huge demands with European football ahead of us."
Romelu Lukaku impressed during his loan spell at Everton last season, but Martinez is remaining coy over whether the Belgium striker can be lured back to the club from Chelsea.
"Rom fits in really, really well at Goodison," he said: "We created a fantastic bond with the player, and the player with the fans, and that is something that we would love to extend.
"It is difficult to say because he is not our player and I would never be disrespectful in that respect. He enjoyed his time at Everton, he developed as a footballer and we hope the parent club, Chelsea, were very happy with that loan relationship.
"Whatever happens in the future, at the moment there is not much we can speak about."
