Davies has scored an impressive ten tries from 19 appearances in the RaboDirect PRO12 for the Scarlets and his reward is a place in Wales' Possibles team against the Probables for Friday night's trial at the Liberty Stadium.
That game will go some way to deciding the 31-strong squad for the two Tests with South Africa and the warm-up match with Eastern Province Kings in Port Elizabeth on June 10.
But former scrum-half Howley says uncapped Davies has every chance of breaking into the reckoning.
"Gareth has been the form scrum-half in the RaboDirect PRO12 with the number of tries he has scored, his ability to score tries from ten yards and 50," Howley told Wales Online.
"Mike (Phillips) is one of the most competitive people and I am sure it will be quite fiery. That is what Probables and Possibles should be like. It will be an intriguing battle.
"When you are playing a decision-making position, continuity and knowing you are playing regularly is important.
"Things become automated and Gareth has developed that having been selected more regularly in the last 12 months than before."
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