The 29-year-old was marginalised by the Portuguese during the first half of the campaign, but has impressed under the new head coach, Tim Sherwood, scoring six goals in nine Premier League matches.
"Adebayor is back and has been unbelievable," Vertonghen said. "Just one player coming in can sometimes affect the team.
"When we played Liverpool and lost 5-0 (in Villas-Boas's last match at the helm), we had a lot of injuries and sometimes a manager can be unlucky.
"Of course, he had the Adebayor thing and some difficult business to take care of.
"We lost against the big teams and that is why we couldn't compete for the top-three places."