Hemmings replaced Andy Keogh to play the last 22 minutes in the 1-1 draw at Barnsley and used his pace and movement to great effect, troubling the Tykes' defence on numerous occasions.
And Vokes, who played up front alongside Hemmings, thinks the teenager has all the tools he needs to make it to the top.
The Welsh international said: "He's a young lad, nippy with good feet and if he can come through and push on when we're in the Premier League next season, it will be a massive experience for him.
"It's great for him. I've trained with him all season and (played) with him in reserve games and I'm buzzing for him. To come and play your first game amid those scenes was great for him.
"It was a great experience for him. It wasn't the easiest game to come into and play, especially in his position, but I think it will be one of many for him."