Villas-Boas was advised by his medical staff to omit Lloris from the squad after the French international sustained a head injury in the game against Everton last week but stayed on the pitch for the final 12 minutes.
He said the decision to play 42-year-old Brad Friedel, who made his 450th Premier League appearance, was in no way admitting he made a mistake.
"The medical department thought it was a bit too soon to play him (Lloris) today. Had the game been tomorrow he would have played and I expect he will play for France (in their World Cup playoff)," Villas-Boas told reporters.
France travel to Ukraine for the first leg of their World Cup playoff match on Friday.
"Clinically and medically all the signs were that he could play on last week. They gave him a different test this week called the 'Impact Test' and they decided he should not play," Villas-Boas said.
"Nothing else came to light during the week and I stand by my decision to carry on playing him last week."
He bemoaned his side's bad luck to come up against an inspired goalkeeper in Tim Krul as Newcastle grabbed the points in a shock 1-0 Premier League win at White Hart Lane on Sunday.
"Obviously we have look at ourselves and recognise our first half was very poor so that's a negative," Villas-Boas said.
"But the positive part is that we reacted so strongly and the result is unfair bearing in mind what we created, especially in the second half, but Tim Krul was key to the game and made the difference.
"I still think that if one of those opportunities had gone in we would have won the game."