Warren Gatland will also have Rhys Patchell available following his hamstring injury which he sustained in December.
Halfpenny has been out since suffering concussion in the victory over Australia in November.
“It’s great to see him running around with a smile on his face,” Scarlets head coach Wayne Pivac said of Halfpenny.
“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.
“He goes back as ‘available’, in consideration for Wales, and if they feel they need a game, we’ll slot them in (against Benetton).”
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“Both trained with us yesterday (Monday) and did everything with contact, both passed with flying colours. They’ll return to Warren and his Wales group, and they’ll make a call as to what they want to do from there.
“We’ll get a message as to who if any are released after Wales training Wednesday.
“Patch has also been out for a number of weeks and it was good to see both of them flying at everything, both can’t wait to get on the field.”
Speaking in January at the Six Nations launch Warren Gatland insisted that Halfpenny would not be rushed back.
The Wales head coach said: “For us, it’s [about] easing Leigh back in slowly. It’s been tough for him but he’s been philosophical; he’s lucky his partner has given birth and he’s been working on his kicking with Neil Jenkins.
“His well-being is the most important thing for us.”
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