The Trotters appear to have missed out on re-signing Daniel Sturridge after the England Under-21 international said he was going to stay at Chelsea for the forthcoming season and fight for his place, having spent time on loan at the Reebok last campaign.
Last season’s top-scorer Johan Elmander departed on a free transfer to Galatasaray and is yet to be fully replaced, but Coyle has suggested they are not quite done with their summer dealings following the purchase of Darren Pratly from Swansea.
Speaking to Sky Sports News, Coyle said: "We've lost a couple of players and we're looking to add quality to it.
"The players we are after I believe have the necessary quality to enhance Bolton Wanderers.
"It's always difficult because the market can swing from one end to the other and the prices can rise.
"So you can only do the best business you can for the football club and we're quietly pleased at the moment, but I would like another couple of faces to come in before the start of the season proper."
Trotters fans won't be expecting any huge transitions as Coyle looks to improve on last season's finish of 14th.
“I don't think there's major changes but I think there is always little tweaks. The great thing for me is that there are open discussions, so we can try and move the game forward and make it better," he added.
"We're working hard, everybody enjoys pre-season, there's extra conditioning and makes you ready for the start of the season on August 13th.
"We all have that sense of anticipation and excitement when it comes about, but it's important you do all the preparation work prior to that."
"Nothing is finalised as of yet, we're in the process and not jumping the gun, but it's important that we bring some freshness in."