The Cherries' manager said the Frenchman has been training with the club for the past two days and his complete preseason with former club, Lille, means he is physically ready to play.
The Frenchman could be in the line up for the Cherries as soon as the club's curtain raiser against Liverpool if he can learn team concepts in time, Iraola said.
The Bournemouth manager said: "He has come this week, has trained two days with us.
"I think he has trained well, but we will decide. It has pros, cons.
"I think he is physically definitely ready.
"He has done a complete preseason with Lille.
"He played a lot of minutes so he's ready to go and it's a matter now of getting all the concepts quickly, in terms of, you know, of every team in all different phases of the game.
"I hope he can do it quickly and if it's not tomorrow, will be next week because I think he's a very good player."
The Frenchman joined the team after the departure of both Dean Huijsen and Illia Zabarnyi to Real Madrid and PSG, for a fee of €35million plus €5million in add-ons.
That fee is the second-most the club has paid for a player, after they bought Evanilson for a total fee of up to £40.2million.
Diakite is the first centre back the Cherries have signed this summer, with Iraola making it clear that he needs two in the remainder of the window, to ensure Huijsen and Zabarnyi are replaced.
When asked if he was always planning for life without Zabarnyi, Iraola said: "No. You have to be prepared for everything.
"You don't know what's going to happen.
"It's true that they were news very early in the summer, I would say even before starting preseason.
"So, it's something that could have happened and it has happened, but we have to adapt.
"The club is doing their job.
"In some scenarios like the Milos one, everything happened quite quick.
"We signed Adrian (Truffert), even with the keeper, we signed Petrovich, they've done a complete preseason with the centre backs, it has probably has cost us more but it's normal things of every summer, especially when the window closes so late now after four games.
"I think it's a lot."