Manchester United's potential was on display in Wednesday's entertaining 3-2 Premier League win over Newcastle United as three of the team's least experienced and youngest players - Kobbie Mainoo (19), Amad Diallo (21) and Rasmus Hojlund (21) - scored.
"I see the positives, I see that this team is developing, I know the reasons why we are not performing," Ten Hag said. "No team will perform when the whole (injury-depleted) back four is not available, across the season.
"Even striker Rasmus Hojlund, three times injured, (Marcus) Rashford also injured, so we have had our problems across the season and that has a negative impact on the results.
"(But) you see players performing and you see players progressing like the youngsters and that is very positive, there is a high potential in this club. So, there are also many positives in this season, but I can't mention this. You know why - at the end of the day, we have to win trophies. And in the Premier League, and in the Champions League, we didn't perform what people expect from us."
Ten Hag's men remained eighth in the table with Wednesday's win but level on 57 points with seventh-placed Newcastle in the fight for a European berth next season.
The victory at Old Trafford in their home finale felt like a reward for fans who have endured one of the worst home campaigns in the club's history, and Ten Hag addressed the supporters he called the "best in the world" after the final whistle.
"We wanted to thank them for sticking with us, we are in difficult times," he told Sky Sports. "We are in a transition at this club and the results are not what we expect. We also have our reasons, but it's still a disappointing season.
"I am very pleased (with Wednesday's win). In the past months we had many games where we were in winning positions but we couldn't get over the line."
If Ten Hag's men win the May 25th FA Cup final versus holders Manchester City, they will play in the Europa League next season. However, if City win, United will need to finish seventh to secure a place in the Europa Conference League.
Manchester United, who have never finished lower than seventh in the Premier League, play at Brighton on Sunday and need to better Newcastle's result at Brentford on the same day to move up to seventh place.
