Koeman revealed after Saturday's 1-0 pre-season friendly loss to Bayer Leverkusen that a deal appeared close for the 26-year-old Celtic stopper, with the clubs having reportedly agreed a fee of around £10million.
"Of course we are interested, of course he did the medical tests, but for yesterday afternoon I have not spoken to the board and maybe when I go up for a drink they will tell me that," Koeman was quoted as saying by the Daily Echo
"For sure we are interested, but I didn't hear he has signed."
Koeman also said the Barclays Premier League club had had a bid - believed to be in the region of £4.5m - rejected by Leeds for right-back Sam Byram.
Press Association Sport understands other top-flight clubs have also enquired about the highly rated 20-year-old
"We lost (Calum) Chambers to Arsenal - it (Byram) was a player we had on the list and it's true that we had a bid for him, yes," the Dutchman said
"What I heard was that Leeds didn't accept it."
Source : PA
Source: PA