Williams was hit with a grade two shoulder charge from a hit on South Sydney prop George Burgess in the clubs' NRL season opener.
Williams will sit out games against Parramatta, Brisbane and Manly after taking the early guilty plea.
Roosters five-eighth James Maloney said Williams wasn't happy when informed of the NRL match review committee charge.
"He was disappointed, disappointed is a pretty media friendly word isn't it?" Maloney said on Wednesday.
"Apparently it deserved two weeks because it's what they have ruled.
"It is out of our control, there is nothing we can do about it, we move on and see him back in three weeks.
"There always seems to be a bit of inconsistency there.
"I didn't agree with it (the shoulder charge) coming out of the game, but it has been and gone now."
Prop Sam Moa said Williams was bitterly disappointed to be missing three games in his final year in the NRL before he rejoins New Zealand rugby.
"He was devastated when he found out the grading," Moa said
"He didn't want to miss any games.
"He was really disappointed because he felt he let the team down.
"But he is a professional and he will be training hard as hard as he can to get back.
"It is a big loss having him out. But we have got the depth to cover for that and that will hold us in good stead.
"It gives another guy an opportunity. We will get the job done."
The Roosters play big round one winners Parramatta at Allianz Stadium on Saturday and Maloney said they were keen to atone for their 28-8 round one loss to Souths.
"We were disappointed in the way we played," he said.
"The effort was there but it was just a little bit of poor execution in our defence and attack.
"There is a bit to work on. We were a bit rusty across the board, we got what we deserved and we have this week to fix it up.
"Parramatta played well last week and they will be looking to keep their winning run intact."
