The Manchester City loanee's arrival has been a major boost amid the club's relegation battle, says the long-serving striker.
Sinclair, 25, had earned a meagre three starts in two-and-a-half seasons with big-spending Manchester City before joining Villa on a six-month loan deal in January, with injuries and poor form wrecking his time at the Etihad Stadium.
The former England Under-21 international also struggled to make his mark during last season’s loan spell at West Bromwich Albion, featuring just 11 times, and made just four cameo appearances for a total of 29 minutes for Manuel Pellegrini’s side over the first half of this term.
However, the forward has shown clear flashes of his past Swansea form since arriving at Villa Park, grabbing three goals in eight appearances, and now looks to have nailed down a regular starting spot in new manager Tim Sherwood’s line-up.
With the club having the option to make his move permanent in the summer, the Daily Star reported following the 4-0 win at Sunderland that talks have now opened over a £3.5 million deal.
That news will come as welcome news to Agbonlahor who, in an interview with young Villa fan Moin Younis, was quick to praise his teammate’s qualities and determination to succeed in a claret and blue shirt.
“He’s a quality player,” the long-serving forward said. “He’s not played a lot of football recently but he’s determined to get back playing again.
“He’s added a lot of quality to the squad and he’s doing really well.”
Sherwood himself has declared his interest in keeping Sinclair at Villa for the long-term if his current form continues, having been quoted in the Express as declaring: “Has he a future here beyond the summer if he continues to perform? Yes - and I think he is eager to do that.
"It is a huge club, he realises that. He obviously wants to play in the Premier League, as we do, so it is something that can be discussed once we are safe - in a couple of weeks!"
Having been tipped for a senior England call-up during his time at Swansea, Villa could well have a potential bargain on their hands in Sinclair if he can remain fit, in which case some thanks might need to go to the since-departed Paul Lambert for managing to bring him to the club.