Steve Cooper knows the Foxes need new recruits to make them ready for the Premier League. They have already made four signings - including defender Caleb Okoli from Atalanta - but the manager wants more.
They are keen on Juventus' Matias Soule for their return to the top flight after one season in the Championship.
The goalkeeping situation has also changed at the King Power with No.2 Jakob Stolarczyk ruled out for up to six months after ankle surgery.
"We definitely have to bring players in - everybody knows that," said Cooper after Tuesday's 2-1 friendly win at Shrewsbury.
"Sometimes it's not easy to do and I understand that as well. You've got to bring the right players in.
"But we've got to make sure when that first game comes we're in with a chance of being able to what we need to do in the Premier League.
"It's not as clear as saying we need players in this and that position... there are certain profiles of players and attributes we need and I'm clear on that.
"I'm not going to say we need 'X' amount of players because if you get more it sounds like there's no plan. There's a clear plan and hopefully we can get a few signings over the line and like all managers say, the quicker, the better."
A deflected Stephy Mavididi free kick and Kasey McAteer's winner came either side of an Okoli own goal in Shropshire.