Berahino wrote on Twitter "time to be selfish".
Clarke said: "I didn't see the tweet.
"I thought the contract was almost done.
"As far as I know, the club have made him a really, really good offer and we're just waiting on his agents sorting it out.
"I don't think there is too much more negotiation to be done.
"He just has to put pen to paper on the deal - it's a good deal."
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