Steven Smith will become Australia's 45th Test captain after being confirmed to replace Michael Clarke as leader for the remainder of the series against India. Smith has officially taken over the Test vice-captaincy from Brad Haddin as Australia's selectors sought a more long-term solution than temporarily handing control to the 37-year-old Haddin.

"As a captain first and foremost I'll try to lead from the front with my performance on the field, and with regards to tactics I think we've been pretty good this year," Smith said in Brisbane. "Pup's been amazing with what he's done and the group we've got at the moment going forward. I don't think there's any real need for a big change there."

Smith, 25, had widely been tipped as the next full-time captain after Clarke but had not previously been groomed in an official capacity in the same way Clarke had been as vice-captain under Ricky Ponting. However, the uncertainty surrounding Clarke's fitness given his ongoing hamstring and back problems prompted a rethink from the selectors.

"These are difficult circumstances given Michael's injury and the fact that we don't know how long he will be out of the game," national selector Rod Marsh said. "What we do know is that it won't be an overnight fix so after a lot of thought we have taken the opportunity to appoint an emerging young leader as captain until such time as Michael regains fitness and returns to the side.

"We congratulate Steve on the wonderful honour of leading his country. On Wednesday he will become Australia's 45th Test captain and at the age of 25 will become one of our youngest leaders. He is an exceptional young man who is highly regarded by the National Selection Panel not only for his fine performances with the bat but also his maturity and clear leadership potential.

"Brad Haddin has done an exceptional job as vice-captain since assuming the role last year and will provide strong support to Steve just as he has done for Michael. There was a strong argument for Brad to assume the captaincy until Michael returns, but given we don't know how long that will be, we felt the time was right to take a longer-term view and give a young player this chance."

Haddin, who led the side on the final day of the Adelaide Test while Clarke was off the field due to his injured right hamstring, will serve as Smith's deputy for the Brisbane Test, which starts on Wednesday. The changes were recommended by the selectors and endorsed by Cricket Australia's board on Sunday night.

"The board fully endorsed the recommendation put forward by the selectors," Wally Edwards, the CA chairman, said. "Steve is an impressive young leader who deserves high praise for his temperament and on-field performances to date. We believe he will do an excellent job when given the chance to captain his country against India."

Marsh's fellow selector Mark Waugh said the opportunity provided by Clarke's injury meant the panel decided to look further into the future than simply a stand-in leader for one match, as Haddin would have been.

"Brad Haddin would have done an excellent job as well, he did a great job captaining the side on the last day in Adelaide," Waugh told Fox Sports. "But Brad's getting towards the end of his career, he's said he probably wants to go if his form's good enough to the Ashes next August, so taking all that into account, the fact Brad's probably not going to be there beyond that, common sense says it's a good time to blood someone a bit younger who's going to be around for the next 10 or so years.

"That's the reasoning behind it, Brad will contribute greatly as he always does in the vice-captain role when Steve captains. He's a very important member of the side, he's well respected and I'm sure he'll be a great person to lean on for Steve Smith over the next few matches.

"I have no idea about Michael Clarke's fitness and I don't think anyone can really, clearly state how long Michael's going to be out. Hopefully it's not for long, but we've seen in the past few months he's had a lot of problems with his back and his hamstrings. Steve is captain until Michael comes back and who knows when that will be."

Smith will become the third-youngest man to captain Australia in Test cricket, behind Ian Craig and Kim Hughes. Clarke has already said that he will need to consider his future given the recurring nature of his hamstring and back injuries, and it raises the possibility that Smith could effectively be stepping into the role on a full-time basis.

Although he has not been groomed in the way Clarke was, he has captained Australia A and New South Wales in recent years and captained the Sydney Sixers for the first time at the age of 22 - Haddin serving as his deputy. With both the Sixers and the Blues, Smith has led trophy-winning teams: the inaugural BBL title in 2012 and the Shield earlier this year.

Smith is regarded as having a natural cricket brain, and has also added notably to his skills off the field in recent times. His confidence as a media speaker has grown, while senior CA figures have also been impressed by the stability he has attained in life through a long-term relationship with his girlfriend Danielle Willis.

During the recent series against Pakistan in the UAE, Smith told ESPNcricinfo that managing players and gaining their respect was the hardest part of captaincy. "The toughest part of the job is managing all the players around you," Smith said in October.

"The on-field stuff, setting fields, changing bowlers, that's the easy part. It's making sure all your players are on the same page with what your plans are and what you want from your players and the team. That's the biggest challenge and what you really need to get right if you want your team to be successful."

First chosen for Australia's Test team in 2010 as a leg spin bowler who batted at No. 8, Smith has grown in confidence and application as a batsman since those early appearances, grooving his technique and scoring runs in all conditions.

His development was noticed by Chris Rogers in 2012, and since his recall to the Test team in India in 2013, Smith has crafted five hundreds and lifted his batting average to 46.02. In Adelaide he notched his highest Test score, 162 not out.