Daniels has impressed in the position since slotting into the Park Hall club’s back four earlier in the season.
Harrison said Daniels ‘has done brilliant’ as Saints, who are seven points clear at the top of the JD Cymru Premier, get ready to face fourth-placed Penybont.
Saints are unbeaten in the league this season, taking 37 from a possible 39 points, and have won their last 12 league matches in a row.
“Josh has done brilliant,” said Harrison. “He’s done really, really well. He’s fitted in that right back position really well. He defends better than a normal winger would.
“He’s good in the air. He’s not the biggest in the world, but he’s got a fantastic leap and he’s aggressive with it, so he’s got all the attributes there to be a really good full back and at this moment in time he’s the best full back in the league.
“You look at it and through his form and the way he’s playing from that position, it’s suiting him at this moment in time.
“It’s not his first choice position, but again he wants to play desperately. He’s found himself playing right-back through injuries and previously playing there for Shrewsbury Town – and he’s embraced it and ran with it and the place is his at this moment in time.”
Saints maintained the winning habit with a 2-1 victory over Caernarfon Town in the third round of the JD Welsh Cup last Friday night.
They have been given another home tie in round four of the competition with Newtown handed a trip to Park Hall in January.