MELBOURNE (REUTERS) - Shattered Australia captain Lleyton Hewitt has said his young Davis Cup team will be better for their heartbreaking semi-final loss to Belgium and backed them to bounce back quickly from the disappointment.

Chasing their first appearance in the final since winning the 2003 title, Australia led 2-1 heading into the final singles matches in Brussels on Sunday, but Nick Kyrgios and Jordan Thompson met their match against David Goffin and Steve Darcis.

Hewitt said he could not fault the effort of his players in front of a parochial home crowd on clay courts, their least-preferred surface, but as a member of the team that beat Spain in the 2003 title-decider, he was still crushed by the defeat.

"You come here to get the result. It's a bit raw at the moment," the two-time Grand Slam champion told reporters.

"Everyone gave 100 per cent. We left it all out there. But that doesn't make it hurt any less.

"It's disappointing, but I've told the boys, if it hurts it's because it means something.

"These boys take a lot of pride wearing the green and gold and will bounce back."

With Bernard Tomic overlooked for the tie amid a deep slump in form, Hewitt sprung a couple of selection surprises over the weekend, neither of which paid off.

After including the in-form Thanasi Kokkinakis in his squad, Hewitt ignored the young talent and plumped for 183rd-ranked John Millman, who lost the opening singles to Goffin on Friday.

Millman played well in the defeat to Goffin, but was discarded in favour of 69th-ranked Jordan Thompson who duly lost to Darcis on Sunday.

"It was always going to be the case for a long time (to play Thompson on Sunday), so nothing in our plans changed," Hewitt said, defending the decision.

"A lot of these boys haven't played in Davis Cup ties away from home," added Hewitt.

"It is different. It's tough. Especially in semis and finals. They'll be better for the run."

Belgium will play away to France in the decider in November.