Green's season-long loan from Aston Villa ended on Thursday morning, with Villa loaning him out to Charlton Athletic for the second-half of the campaign.
He made only four substitute appearances in the Championship, together with two starts in the Carabao Cup.
Neil cited the strong start to the season made by players in Green's position as a reason for him struggling to make an impact.
Tactically, the type of winger the 21-year-old is perhaps didn't suit North End's style.
Speaking at the Springfields training ground, Neil said: "Andre is a good lad. We brought him in hoping to get him game time and see what he could do.
"Unfortunately he found it difficult to get into the team. The start the players had to the season made it extremely difficult for him.
"Sometimes I think the more that you are not in the team the more you drift and the more difficult it becomes at that point.
"Obviously your fitness levels drop, even the motivation in terms of trying to get himself to show what he can do.
"Particularly when you are on loan, sometimes that can be be tough because you know this is not your permanent club.
"So when players are not in the team it can be a bit more difficult."
Five of Green's six appearances came in the first month of the season, the sixth being in October against Leeds at Deepdale.
He will join his Charlton team-mates for training on Friday, with him not set to feature in the Addicks' visit to Swansea on Thursday night.
Neil said: "A difficulty we had is that Andre wanted to hug a touchline, he is an out-and-out wide player whereas our front three come inside and run beyond - they just play slightly differently to the way he played.
"I think he found it tough to adjust to that. The lads were performing very well and it become more and more difficult for us to find opportunities for him to play.
"We felt for his career and for him, it was better that he goes and plays football. The last thing I want to do is stall anyone's career.
"If someone is not playing, I generally actively try and help them.
"Don't get me wrong, there are some players that are in different scenarios where they are still developing as players.
"Andre is at the age now where he needs to play as often as he can. More so the fact he managed to put together a set of games last year at Aston Villa.
"When you are used to playing at this level you want to continue that. If you come from a lower level it takes a bit of time."