Stevens never really broke into Villa's first team, despite going on to feature for the Republic of Ireland Under 21's.
He won the Irish Premier League's young player of the year award in his last season at Shamrock Rovers, but ended up making just nine appearances at Villa Park, all of which came in the 2012-13 campaign.
Most of Stevens' football came in loan spells, with Doncaster taking the player to the Keepmoat Stadium on two separate occasions, and he made 32 appearances last season as Paul Dickov's side finished mid table in League One.
The 23-year-old has now dropped down another division though to sign with fallen Premier League side Portsmouth, who are seeking to put together a team to take them back up the divisions after a five-year spell that has seen three relegations as they battled administration. Stevens spent a short time on loan at Northampton at the start of last season.
Pompey boss Paul Cook was very happy with the deal, telling the Portsmouth website: “We’re delighted to bring Enda to the club. He brings a lot of quality and adds balance to the left-hand side.
“It’s important now that he kick-starts his career and has aspirations to progress and perhaps get into the Ireland squad.
“He’s got all the talent in the world, but he has to knuckle down with us and be the player that I believe he can be.”