Sels finished the season as the Premier League's Golden Glove winner, becoming the first keeper outside of Chelsea, Arsenal, Liverpool and the two Manchester clubs to win it.
Hennessey told Forest's website: “It's an amazing achievement.
“The Golden Glove normally goes to a team in the top six, and most often to the champions. For Matz to have won it is incredible and we are all so happy for him.
“I’ve always believed the biggest thing in the Premier League is consistency, and I thought throughout the whole campaign he was outstanding. It wasn’t just in the league, he obviously also played a major role in our cup progress, he was superb in the penalty shoot-outs.
“Every part of his game is excellent, which he proved in this season just gone. The shot-stopping, coming off his line to catch, dealing with set pieces, the decision-making, he handled everything really well. For me, he is one of the best in the league. I watch goalkeepers all the time and I think he is definitely up there. His record and the team’s performances prove that.”
Mats lives it every day
Hennessey also highlighted the influence of the Forest staff on Sels' form.
He contined, “In the Premier League, everything is quick, so for him to adjust how he has, coming from the French league, which is a good league, is impressive. Everything that happens in the game here is just at an extra pace. And from a goalkeeper’s point of view, he has settled in really well and grown ever since.”
“He is a very hard worker, that hasn’t changed from the first day he came through the door here until the last Chelsea game. Every day he pushes himself and he is a pleasure to work alongside. He’s also really willing to learn. We say as goalkeepers that every day is a learning day and Matz lives that way.
“Rui Barbosa is a fantastic goalkeeping coach and every day we work hard together, and that’s not just on the grass or in the gym. It’s also in the meeting room, watching clips, thinking about what we’ve done well, what we can improve on. Matz is good at embracing that which is a credit to himself.”