The midfielder has become a regular under Paul Lambert after struggling earlier in his Villa career to maintain his fitness levels.
A cruciate ligament injury in April 2010 halted Delph's progress at Villa Park but he has since returned to fitness and form.
The 24-year-old was laid low by a virus in recent weeks, forcing him out of the games against West Ham and Cardiff City, but he is back in contention to face Southampton.
"I feel fitter and stronger than ever," he told the club's official website. "That probably has something to do with me starting to put some performances together.
"I didn't stop at the end of last season. I had maybe a week off but then I was back in the gym, working hard and putting in some good shifts.
"When pre-season came around I felt really strong. I've had a run of games from January, which is something I hadn't really had since I came here.
"I should have played far more games than I have. When I was at Leeds I made something like 50 appearances in one season, so to only have played 70-something in the last four years is pretty poor.
"But I love it now. Everyone gets on and we are like a close-knit family."
