Finn Russell will return to Scotland action against Wales on Saturday.
The Racing 92 playmaker was badly missed a fortnight ago as he sat out the Dark Blues' Guinness Six Nations defeat to France in Paris having suffered a head knock on club duty.
Russell takes over from Pete Horne for the visit of Warren Gatland's men while the team will be skippered by Stuart McInally, Regular captain Greig Laidlaw is replaced by Ali Price at scrum-half.
Edinburgh prop WP Nel and club-mate Darcy Graham also start as lock Jonny Gray and wing Tommy Seymour make their 50th Test appearances.
Head coach Gregor Townsend said: "Getting to 50 caps for your country is a milestone in a player's career and it underlines the consistency and quality both Tommy and Jonny have delivered for Scotland over the years."
"Tommy has started all his games and has an impressive try-scoring record, which is a fundamental element of the game for a winger.
"As well as his finishing ability, his excellent work rate off-the-ball and outstanding aerial skills have been the key reasons why he's reached a half century of appearances for Scotland.
"Jonny is an exceptional player who came through as a young man and, by becoming the second-youngest player to win 50 caps, shows just how well he's played in that relatively short time.
"He has a phenomenal work rate, is a very accurate tackler and takes real pride in helping the team prepare, as well as continually looking for ways to improve his own game."
BREAKING | Jonny Gray and Tommy Seymour will make their 50th appearance in a Scotland side – that features four changes – against Wales in the Guinness Six Nations this Saturday at BT Murrayfield (kick-off 2.15pm) – live on BBC.
— Scottish Rugby (@Scotlandteam) March 7, 2019
4️⃣ ➡️ Russell, Price, Graham & Nel all start pic.twitter.com/BflNT5FtNp
Scotland are looking to bounce back after successive defeats to Ireland and Les Bleus but Townsend knows Grand Slam-chasing Wales present another major hurdle.
He said: "Wales have a very good record against us and are in excellent form. It's a similar challenge to the one we faced last year against England, who had also been on a very good run of results in their preceding games.
"We rose to the challenge that day and found a way to win and I firmly believe we can reach that level of performance once again on Saturday."
Scotland: Blair Kinghorn; Tommy Seymour, Nick Grigg, Pete Horne, Darcy Graham; Finn Russell, Ali Price; 1-Allan Dell, Stuart McInally (capt), Willem Nel; Grant Gilchrist, Jonny Gray; Magnus Bradbury, Jamie Ritchie, Josh Strauss.
Replacements: Fraser Brown, Gordon Reid, Simon Berghan, Ben Toolis, Hamish Watson, Greig Laidlaw, 22-Adam Hastings, Byron McGuigan.
Wales's centre Jonathan Davies referenced Wales's defeat in Murrayfield in 2017 as his coach Warren Gatland names the team for they hope is the fourth leg of a fourth Grand Slam in 15 years.
While they have toppled Scotland in 11 of the countries' last 12 meetings, they came badly unstuck at Murrayfield two years ago, losing 29-13 after leading at half-time.
"They will be looking to start well and get the crowd behind them and make sure they put us under pressure," Davies said.
"But for us it's making sure we build on the momentum we've got now, and as a unit we stay pretty tight.
"Two years ago we were well beaten there, so we can't take them lightly. It is going to be a very tough Test match.
"The squad is very tight. We've got momentum, and we are making sure we keep that. The squad is reacting well to the expectancy of winning games, and that's a good place to be."
Wales: Liam Williams; George North, Jonathan Davies, Hadleigh Parkes, Josh Adams; Gareth Anscombe, Gareth Davies; Dylan Evans, Ken Owens, Tomas Francis, Adam Beard, Alun Wyn Jones (capt), Josh Navidi, Justin Tipuric, Ross Moriarty.
Replacements: Elliot Dee, Nicky Smith, Dillon Lewis, Jake Ball, Aaron Wainwright, Aled Davies, Dan Biggar, Owen Watkin.
