The on-loan West Ham striker found the net as Stuart Pearce's England youngsters beat Macedonia on Friday.
But Sears has yet to register a goal since moving to Selhurst Park - although he was robbed of one when his effort at Bristol City was infamously disallowed despite clearly crossing the line.
"He needed a goal. The disallowed goal at Bristol City knocked the stuffing out of him a little bit but he will come back better having scored for them," said Warnock. Not scoring does play on a striker's mind."