"He was treated pretty harshly by England, in my opinion, but the way he has coped since returning to us has been a terrific example to everybody.
"Matthew has not moaned once about his luck, he has just got on with his work and been positive. That burning ambition to play for his country is still there, stronger than ever."
After scores of 62, 105 and 59 in April, Prior's May returns were 51 against Surrey, one against Somerset, a brilliant 131 and 64 against Nottinghamshire, followed by nine and a stunning 133 not out against Durham.
Prior, skippering Sussex for the first time in the absence of the injured Chris Adams, did his Captain Marvel impression by hammering 133 out of 176, having arrived at the crease at 24 for three.
However, Sussex lost by seven wickets with another England discard, Durham's Steve Harmison, doing the damage taking seven wickets - including a hat-trick.
After the keeper's previous century on a bowler-friendly Trent Bridge track, Adams insisted that Prior is talented enough to play for England as a specialist batsman.
"I believe he could comfortably bat for England at five or six," said Adams. "He has a Test average above 40 and he's playing better than ever now."
But there is no question of Prior hanging up the big gloves. He only has to glance at his new mentor to remind him what is possible.
Robinson is glad of the Stewart link-up, and is expecting Prior to continue improving under the former England skipper's tutelage.
He said: "Alec's management company look after Matthew's affairs and through that link Alec has been working with us as a part-time coach.
"He is very knowledgeable and a great bloke to have around on training days. He spends a lot of time with Matthew."
