The academy-reared player was outstanding in last season’s fight against relegation, coming back after a loan spell at Bradford City to show he belonged in the second tier. The second season is notoriously difficult but after injury problems at the start, the 22-year-old has grown in stature and, in his coach’s eyes, become a leader.
“He’s matured a lot this season,” said the Spaniard. “It’s different playing your first season as a first-team player surrounded by many good players to this season where he’s one of our main players and he needs to take a lot of responsibility.
“It’s also different when you are playing Saturday to Saturday or every two or three days.
“We didn’t have him for the first five games but the moment he started to play, he hasn’t missed many minutes.
“Since that first period, he’s the player we’ve used the most. He’s played nearly every game and every minute. Minutes in a row are harder.
“His maturity has been fantastic, I think his progress has been excellent. I think he’s a Premier League player.”
The midfielder, who has also been used in various roles on the left, captained a young team in the final match of last season and has impressed Corberan with his leadership and will to win.
“He leads by example,” he commented. “You have different types of leaders. Some lead by example, some more with words, some with experience.
“O’Brien is never waiting for my message to give 100 per cent on the pitch, the motivation comes from himself. Fortunately, I have more than one player with this mentality.”