Villa’s talisman has now staked a claim to be an England regular following a 10-day spell that saw him put in outstanding displays against the Republic of Ireland, Belgium and Iceland.
Now the 25-year-old is back with his boyhood club and preparing for tomorrow’s clash with Brighton.
And Smith admitted he was delighted to see his skipper wow the nation while away with the Three Lions.
“It hasn’t surprised me what he (Grealish) has done on the international stage,” the boss said.
“I get to see him day in day out and I’ve seen him in the Premier League against some really top teams.
“He doesn’t need a confidence boost, he is a confident player and a confident lad.
“He knows he has got ability but going and doing it on the world stage – against the number one ranked team in Belgium – and playing as he did will give him a lot of confidence.
“I was proud to see him performing – I was also pleased to see him come off the pitch after 76 minutes against Iceland as well.”
With Grealish starting all three of England’s matches, Smith was asked if he is concerned with the amount of football the 25-year-old has played recently.
“I’m not concerned,” he continued.
“Our performance people pass on the data of all our players to the performance people and staff at the respective countries the players go to.
“There is a lot of very intelligent people working for these national teams.
“My players have not complained about the amount of games they are playing.
“Obviously, we get a bit anxious about any of our players getting injured when we’ve got a big game against Brighton on Saturday.
“But I wouldn’t stop any of my players playing for their countries, it’s the pinnacle of their careers.
“And as I’ve said many times, I’ve not retired from international football!”
Villa have been very active in the transfer windows over the last two years. But Smith knows keeping Grealish – who signed a new five-year deal in September – is arguably the best piece of business they have done.
“I think it was a big statement that Jack wanted to stay,” the boss added.
“I think it shows he has got great belief in what we are doing at Aston Villa – not just myself and the coaching staff but the owners and the hierarchy above me.
“He has got great belief, we all know it’s his football club.
“He is playing for England now on a big stage.
“But the only way he has done that is by playing well for Aston Villa week in, week out.”