Allardyce has since been sacked by Everton, though, and Williams is already looking forward to next season and Tuesday's international friendly against Mexico.
"It has been frustrating, definitely. But that season is done now and I'm just looking forward to this game and pre-season for the next campaign," he is quoted as saying by Sky Sports News.
"I haven't played since the Uruguay game [at the China Cup] but I've been training every day and trying to keep fit that way. It's always difficult not being involved and you want to play because playing a game is that bit harder.
"But what can you do? I've just tried to stay in shape and I'll just try and use my experience as best I can against Mexico. We'll see how long everyone plays as that's up to the gaffer."
Williams made 34 appearances for Everton across all competitions during the campaign just finished.