Sam Allardyce says both he and Sunderland's players feel "let down" by Adam Johnson after being by misled by the ex-Black Cats winger ahead of his trial.
When he was first appointed as Sunderland boss last October, Allardyce was told that Johnson intended to deny all charges and the 28-year-old, himself, continued to maintain that stance in the dressing room.
Allardyce therefore continued to pick Johnson while he waited for his court date, with the ex-England international making 16 appearances under the Sunderland boss.
But Johnson's admission of one count of grooming and another of sexual activity with a 15-year-old girl on the first day of his trial left Allardyce and Sunderland's players shocked, with the sacked player yesterday found guilty by a jury of a further count of sexual activity at Bradford Crown Court.
Speaking for the first time after Johnson's convictions, Allardyce said today: "Firstly, from my point of view, I wasn't here when it happened but obviously I picked it up when I arrived.
"What I was told was that he would plead not guilty to all charges.
"On that basis we moved on.
"Everything seemed to be alright on the basis of how it was affecting his game and how it was affecting Adam.
"So it was a massive shock when the trial started.
"The club has obviously given out a statement explaining their position.
"My position was what I was told off Adam so the end verdict, and the start, with him changing his plea, was obviously a shock.
"In the end, you can have nothing but sympathy for the victim.
"Justice has been done and he has let everybody down.
"I think if I had to say anything on the players, it's that they feel let down if anything.
"Like me, everybody thought he was pleading not guilty to all charges."
Questions have been raised about Sunderland's decision to continue picking Johnson after the ex-Manchester City man claimed in court that chief executive Margaret Byrne had seen some of the evidence in the case.
But Sunderland issued a lengthy statement yesterday clarifying their position, insisting that they couldn't make any judgement on Johnson until the outcome of the legal process.
"It's very difficult for me to comment on the little information I have got," added Allardyce, appointed by Sunderland seven months after Johnson was first arrested.
"I can only refer back to the club making the statement. All I knew was that he was pleading not guilty all the way through."