The 21-year-old broke into the first team at the Baggies last season and notched five goals for the club in 32 appearances in the top flight, and the forward has already scored three times this season in all competitions.
Irvine told the club's official website: "I had a conversation with him earlier this week actually, saying to him he could be a top, top player. His movement is very good, he can finish with both feet.
"There are things he still needs to work on of course, he's a young player, but he is making quick progress and if he continues with the professional approach he has got then he will progress even quicker.
"In the time I have been here, his training has been really good. He tries really hard every single day. He stays out late to work on his finishing, he loves his football and tries to do everything we ask him to do. I see a really talented young player with a great future."
West Brom face Burnley in their Premier League clash later today.