The club captain lost his place after the 6-1 mauling Saints suffered at Arsenal, becoming the main victim of the defensive inadequacies of the team in the opening weeks of the season.
Replaced by 20-year-old Argentine stopper Paulo Gazzaniga, who was in turn dropped in favour of Artur Boruc for a short spell, Davis appeared well out of favour.
But the 36-year-old has continued to keep himself fit and prepared to play if needed, earning his chance against Reading after Gazzaniga was ruled out with a shoulder injury.
Adkins highlighted the way Davis had continued to work and conduct himself, despite the disappointment of having lost his long-standing number one position earlier in the campaign.
“Kelvin has played, and great credit to him because for the last two seasons he has been magnificent,” said the Saints boss.
“Paulo was injured and Kelvin came in. He has been working so hard on the training ground and that has been demonstrated with his performance today.”
Adkins added: “You can only pick 11 to start a game and if you are not in that 11 you are not going to be happy.
“If you are not not happy, then you question that individual’s desire.
“There is an understanding that: ‘Look, there is only 11.’ “It is about the squad of players who will be ready on the training ground.
“They work ever so hard and conduct themselves right, no more so than Kelvin Davis who deserves all the credit he gets.”