Phelps' bid to matchMark Spitz's historic 1972 haul of seven swimming gold medals has been thwarted by third place finishes in the 4x100m free relay and the 200m freestyle.
Stoddart was Man-of-the-Match with a two-try display in the 40-24 win against the Barbarians in a match to mark the official opening of Parc y Scarlets.
The match will mark the official opening of Agen's new ground and will be a stern test for the Aviva Premiership Rugby side with a month to go until the start of the new season.