Monk admits his captain could have earned a bigger pay-day if he'd quit the Liberty this summer.
"It was a big contract for him," said Monk, Williams having tied himself to the Liberty until the time he turns 34.
"He is going to attract interest and you see him linked every year and he probably could have earned more money elsewhere.
"It's only natural to want to know what else may be out there and if people are making him aware that he could get this or that at other clubs it can turn your head.
"That's why it was important for us to show how much he is worth to us.
"Ash has given good service to the club and he's a figurehead, but he's also a quality player, a big player for the club and an important performer- you can't forget that.
"But he's got a great affection for the club and he said he wanted to stay here from day one.
"We had to show we were committed to him but now he is committed to us as a club and what we are trying to do."
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