The Wanderers have often been described as the "Dad's Army" of the Premiership as their policy is to bring in seasoned internationals on Free Transfers but Gartside says more and more teams have jumped on the bandwaggon.
"Sam (Allardyce) has been making the point that it is a harder market now. There used to be very few clubs fishing where we were at the bottom end of the market for free transfers and older players coming to the end of their contracts. But there are a lot more people fishing there now and it's making it more difficult for us to find the right players."
Recruiting players such as Tal Ben-Haim and El-Hadji Diouf have helped reduce the age of the current squad slightly, but Gartside says the Bolton manager Sam Allardyce is keen to make the policy of bringing in younger players an ongoing thing.
"We are keener to look at the younger end now. Sam wants to lower the age profile of the squad which we did this year. Getting El-Hadji Diouf at 23 brought the average age down, even though we brought in players like Fernando Hierro and Les Ferdinand. It came down by a blip and we are keen to make sure that happens again."
Gartside highlighted the strength in depth which Bolton have aquired over the past two seasons and was hopeful of finding players to come into the club who will help improve that squad depth even further
"We have to find players who will improve our quality but it is harder to replace what you've got when you have a decent squad with good skill levels. That strength is shown by the reserves we have available now to bring in when senior players are injured. There was a game this season when all our substitutes were internationals."