The 44-year-old Vilanova has been receiving treatment for cancer but is back on the training ground with his beloved Barca in a week that also saw Abidal return to the bench a year after a live transplant.
Barcelona, who hold a 13-point advantage over reigning La Liga champions Real Madrid with just nine games to go, conceded a late equaliser at Celta Vigo on Saturday to draw 2-2 - but Hunter expects the club to pull together now and finish the job sooner rather than later.
He told Revista: "I'm straying outside my knowledge if we're talking about long, intensive courses of chemotherapy. What we have learned is that he (Vilanova) has been more engaged in what we've been watching while he's been away. He'd give a video conference team talk before the match.
"Now that he's back, I think that along with Abidal, it's huge. It's not very fashionable to talk about spirit and family bonds within a team. It's more about talent and money, incentives and glory. But since Pep Guardiola took over, it's very much been based on spirit.
"The resumption of duties by Abidal and Villanova will have a huge psychological effect on this team. It's a beneficial thing for them individually but for as a football club as a whole."
Guillem Balague added: "He (Vilanova) came back in the first training session and said 'You've got no idea how happy I am to be in front of you.' When he said that he took his face away because he was breaking down, and then he got back and started making it all football.
"He stressed that they have to get back to focussing on the league, because it's not one yet. The emotion of it all is now very much part of his involvement."
The draw at Celta marked another personal milestone for Barcelona star Lionel Messi, who completed the remarkable feat of scoring against every La Liga side in a row.
Hunter said of the Argentine forward: "Although there's a nice symmetry to scoring against 19 teams in the league, to my knowledge there's no other player who has scored in 19 games in a row. That's outright football history.
"Secondly, Messi used to suffer from a virus that meant he got bad jet lag coming back from Europe and South America. This season, including this weekend, when he laid on one and scored one, he's shown that physically, mentally and physiologically that he's learned to cope with that.
"He's as as devastating when he's tired after an international break as when he's at his absolute sharpest."
Former Liverpool assistant Paka Ayestaran was equally effusive in his praise, adding: "It's a magnificent achievement and it shows that for him, it's never enough. He achieves one thing and then he's on to the next one. He's always looking for a new challenge.
"Sometimes, everybody is looking for him going into the box. He wants to be involved in the areas and with the comeback of Tito, they will have a leader who is driving in the right way in the Barcelona style."
Balague ventured even further, predicting that Messi will wear the Barcelona armband next season as he continues to become an even bigger influence off the pitch as well as on it.
Balague said: "You're going to see him as the captain next season. He's already the captain of Argentina. He used to be shy but that's changed.
"He now gives chats before the games and when he's at Barcelona, he also has a lot to say. He's maturing into a leader and you can see it in the way he plays."