The 24-year-old endured a low-key first season at Tottenham Hotspur.
The Argentine joined Tottenham from Roma for £25 million in 2013 but the winger initially struggled to justify such a hefty transfer fee, making 16 appearances in all competitions.
But the 24-year-old has looked a man re-born since his compatriot Mauricio Pochettino took the reins in North London two years ago.
Pochettino appears to have helped Lamela develop an extra dimension to his game, perhaps a steel to match his silk.
He has played his part to help Argentina reach the Copa America Centenario final, where they face Chile early on Monday morning in the United States.
And Walker acknowledges that despite a slow start to his Lilywhites career, the South American schemer is reminding everybody why he was so highly rated once upon a time.
“I hope he wouldn’t mind me saying it but Erik probably had a few difficult months when he first came in here but I think he’s proved the doubters wrong," he told Tottenham's official website.
“We’ve said it in interviews countless times but you could see in training what he was all about and I’m thankful now that he’s showing it on the pitch and he’s proving to everyone why he was such a hot prospect when he came to Tottenham Hotspur."
Lamela's resurgence is a beacon of hope for the likes of Son Heung-min, who also struggled to vindicate Spurs last term following a £22 million switch from Bayer Leverkusen, but he did show signs of promise toward the end of the campaign.