Great Britain's Davis Cup captain Leon Smith defended his team selection after the hosts failed to qualify for the knockout stage of the competition.

Cameron Norrie, Dan Evans and Andy Murray are top-50 ranked in singles and Joe Salisbury and Neal Skupski are the top and third-ranked doubles players.

Murray played doubles ahead of Skupski.

"Is it that controversial to put your two highest ranked singles players out there? No," Smith told BBC Sport.

"Is it controversial to put the number one doubles player in the world out there? No.

"Is it controversial to put Andy Murray out there on the court here in Glasgow? I don't think so. We believed that was the right thing to do, and that's on me."

Both of this week's Group D ties against the United States and the Netherlands were decided by the doubles rubber, with both ending in three-set defeats.

Murray said he and Salisbury had shown they had the potential to play top-level doubles together when they teamed up at last year's Tokyo Olympics but understood why Smith might face questions about selection, in particular about not playing doubles specialist Skupski.

Skupski and his Dutch partner Wesley Koolhof - who was on the other side of the net on Friday against Salisbury and Murray - were runners-up in men's doubles at the US Open last week.

"I'm thinking the same thing right now ... should I have played or should Neal have played," said Murray, who contributed 11 of the 12 points needed across singles and doubles for Great Britain to win the Davis Cup in 2015.

"And it's easy to think all those things," he said in a news conference. "[But] the reality is the teams we lost to are not settled doubles pairs, as well."

Salisbury's usual partner is Rajeev Ram, who he faced in Wednesday's defeat by the United States just days after winning the US Open title with him.

"If me and Joe played more together I'm sure we'd be an even stronger team," Murray said. "But I don't think we played two bad matches. We actually played pretty well."

This week's Group D results put the Netherlands and United States into November's knockout stage and leave Great Britain playing a tie against Kazakhstan on Sunday where nothing is at stake because both have been eliminated.

"It's difficult to get motivated," Murray said. "The way that we have lost these two matches as well makes that even tougher.

"It's a slight flaw with this format in that you have essentially, on the Sunday, on the final day, there is no tennis. Well, there's tennis, but it's kind of irrelevant."

He added that he was particularly "sad" that Great Britain could not have delivered success on home soil and also wondered how many more chances he would have to help them.

"When you get to my age and this stage of your career, I don't know how many opportunities I'll get to still be part of this team," the 35-year-old said.

"We've got a lot of depth now in the singles and the doubles. Because of that, it makes it tougher."