The Harriers, although seen as a lower league team, provided many Welsh players, especially front row hardmen like Whitfield.
Over the next five years, now as a member of the Newport club, Whitfield was capped for Wales on 12 occasions and scored his first try on the 13 March 1920 against Ireland.
In the 1922 Five Nations Championship, Whitfield was the leading try scorer of the tournament with four tries one against England and France, and two against Ireland.
Wales lost the match heavily, with Scotland running in eight tries, it was Whitfield's only time as captain.
He died on Boxing Day 1927 at the Royal Gwent Hospital after a gastric ulcer operation.