Wellens is currently focused on adding a left winger and a goalkeeper and feels he has enough room in his playing budget to accommodate signings in those positions.
But he says trading players out will be important too as he looks to bolster his squad, and intends to make decisions next week on those who are free to leave.
“At the moment we need a couple out,” he told the Free Press.
“Finances will dictate where we are. At the moment there’s not a lot left in the budget. It will probably allow us to get a left winger and a goalkeeper in and that’s it.
“If we’re going to move on loans, I’d say that if we get a winger and a goalkeeper in, we’d still need five if I’m being realistic.
“Four of those will be loans, along with the one coming in next week.
“The only way we’re going to do that is by getting a couple out.
“I’ve had a good look at a lot of the players this week and decisions will be made in the middle of next week about certain players who will need to look for another club.
“Maybe a couple of the young players, after we’ve played Rossington and Spennymoor, we might start looking to loan them out too.”
Wellens has run the rule over his current squad during the first week of pre-season training and admits some players have altered preconceived ideas while others have backed them in.
He said: “I think you come in, listen to people’s opinions you have an idea, you get to see what people are earning at the club.
“But then when you get in yourself, people surprise you. There’s a couple of lads that have really put the work in with a smile on their face, been really good for a group and it’s swayed me that I really want to work with them.
“But then there’s others in my mind from early doors I’d maybe move on, they’ve just given me more clarity that they’re probably not what we’re looking for and we might need to move them on.”