The forward, a summer signing from Burnley for a then-club-record fee, had struggled for form in the first part of the season but has been rejuvenated since the Argentine replaced Nigel Adkins, scoring three goals in his last four games.
The 23-year-old told TalkSport: "The new manager has helped massively. He's put faith in me to be playing regular games. My role is a lot more free now - it doesn't matter where I drift off to.
|5/1||Jay Rodriguez is 5/1 with Paddy Power to score anytime in a Southampton win over Swansea City
"The results that we are getting are obviously good but the performances we are putting in are even better. We have deserved the points and the wins that we have been getting.
"Since January, I've gained a lot of belief. I've had a run of games since then so I feel a lot more comfortable.
"It was a very frustrating start to the season," Rodriguez admitted. "I was frustrated in myself at times because this is where I wanted to be and I was playing against all these great players but I just didn't think I was showing what I could do.
"You get to see how good these players are - and how good and how different the league is - so it's about how quickly you can adapt to it. The autumn was a bit of a tough time because I wasn't playing but it was all a learning curve for me because you get stronger from times like that. I don't think you can look back and regret things because it's part of football."