The Rotherham United midfielder scored twice at Bolton Wanderers on Saturday. It took him to three for the season but only eight for a Millers career now past 100 games.
Assistant manager Barker says he ought to be doing better to progress his career.
"He certainly should be adding goals with the ability he's got and it's not just technical ability, it's tactical knowledge as well," stressed the former striker.
"He's always speaking up in meetings, he understands the game. He's been sat in our meetings now for four-and-a-half years so if he doesn't understand what we're asking now, we've got a problem.
"Technically and tactically he's very good but physically he's some specimen for his age and he has done it three times in a week, not just in League One but the Championship as well.
"But certainly goals is something he has to add to his game and I think realistically he should have had two or three more this season - I remember a chance a couple of weeks ago where he turned down a shooting opportunity that would have been a clear goal and at the weekend he could have had a first-half hat-trick, which is some statement for a midfielder.
"I just hope the weekend gave him that confidence to say I should be scoring half a dozen goals here, probably by Christmas, really, and setting himself the target of doubel figures by the end of the season."
Barker says wanting more goals from 22-year-old Wiles is nothing new, but if he finds them he can follow the progress of some of his former team-mates, and put himself in the international picture.
"We've been talking to him for years about scoring goals and getting himself recognised," he said.
"Matt Crooks recently moved on from us (joining Middlesbrough), Will Vaulks a couple of years ago (signing for Cardiff City in 2019) realistically couldn't do some of the stuff Wilesey did but weighed in with goals and got themselves noticed on the goalscoring charts on a regular basis.
"If Wilesey adds that and comes away with ten or a dozen goals it will put him on the radar for other clubs.
"He's eligible to play for Scotland and we've been saying for a couple of years he should be around the Scotland Under-21s. he's a bit too old now but there's no reason why in the next couple of years he shouldn't be looking at international call-ups and the same with Jamie Lindsay as well. Between the pair of them it would be brilliant if they got the call-up.
"A big part of what we do is about trying to win football matches, trying to get out of League One, trying to sustain Championship football. However, the bigger picture is we've created international footballers who have also gone on and created international careers playing at higher levels, earned loads of money and all that kind of stuff.
"We have a commitment to those players who sign for us to say we will make you better, more athletic, give you a better understanding of the game."