Before you judge someone, you should first walk a mile in their shoes.

Ricky Sbragia has gone all the way to Portugal as acting Scotland Under-21 head coach and he fancies he can make a sound evaluation of the man he has replaced on an interim basis, Billy Stark. Stark will be in charge of the senior side in a friendly with Luxembourg tonight and has been mooted as a candidate to take the role on full-time.

One of those to back Stark's chances is Sbragia. The former Sunderland manager has worked with Stark as a coach for the Scotland youth teams and is confident his colleague ticks all the boxes required to become a successful replacement for Craig Levein, who has removed as national team manager last month.

Sbragia's own concerns will be to a friendly with Portugal Under-21s tonight, with his inexperienced squad comprising the likes of Barrie McKay of Rangers, Matthew Kennedy from Everton and Celtic's John Herron. The trio have arrived as replacements for Stuart Armstrong, Dylan McGeouch and Tony Watt. However, the interim Under-21 manager was still inclined to promote Stark's chances of landing the top job.

"That's up to the people at the SFA, but he's got the experience – he's been with the under-21s; it's his next progression," said Sbragia. "They ask about experience at international level and he's got that, so I hope he does well. He's got everything you need.

"I spoke to him the other night and he's looking forward to it and seemed really relaxed. He's got a lot of experience at international level so I hope he does well."

Sbragia is expected to unleash Chelsea forward Islam Feruz in Setubal this evening, with the former Celtic prodigy having scored a hat trick on his last appearance at international level for Scotland Under-19s against Switzerland. Sbragia is excited as the Somalian-born player's potential.

"I watched him playing for Chelsea under-21s three weeks ago at Manchester City and he was exceptional," he said. "We play to his strengths a bit more and we got the best out of him at Scotland. He won't be fazed playing for the under-21s. He's playing down every week with Chelsea.

"The only hat trick I have seen better came from Guiseppe Rossi when he was at Manchester United in a Youth Cup final against Chelsea a few years ago. He deserved that because we said to him at the Romania game before the match against the Swiss that he deserved a couple of goals."

Another youngster who is hoping to impress tonight is Marcus Fraser. The Celtic defender has watched as Watt rose to prominence for the Glasgow side and he is ready to follow in his team-mate's footsteps.

"He has shown what young players can achieve," he said. "Hopefully I can take the chance in the same way."