Halfpenny has scored more than 700 points in 80 appearances for Wales, and he has played in three British and Irish Lions tours.
"It's great to see him running around with a smile on his face," Pivac told reporters on Tuesday.
"He did everything - full contact, full tackling. We had a mini-game scenario with no hiding places, and he was taking high balls, getting clattered and did everything he needed to do.
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"He goes back to Wales available, we feed back information, medical team to medical team, and I have passed a little note on to Warren. Warren will make a call on what he does from there."
Wales have won their first two games against France and Italy, and the clash against Eddie Jones' England, who are also unbeaten, is billed as a potential title decider.
(Reporting by Hardik Vyas in Bengaluru; Editing by Hugh Lawson)
