ROB Howley said Jamie Roberts had to be dropped after Wales' defensive horror show against Australia, writes Chris Kirwan.

The 30-year-old has been a lynchpin of the side since making his Test debut in 2008, starting in 82 of his 84 caps.

However, the Harlequins man will wear 23 on his back for tomorrow's clash with Argentina at Principality Stadium after five tries were shipped in the 32-8 hammering at the hands of the Wallabies.

Acting head coach Howley has retained Scott Williams and recalled his Scarlets midfield partner Jonathan Davies, who missed out against the Aussies because of a tight hamstring.

"There were a number of defensive errors in our game and Jamie is the defensive captain," said Howley. "The standard of defence wasn't good enough, and we have made a reaction, made a change.

"Jamie is disappointed. He wasn't the only one who made defensive errors.

"I don't look forward to it, and neither do the other coaches, when you are dropping a player of that experience.

"But when you have the performance which we did in that area, you have to make a change. Jamie understands that.

"In fairness to him, when we met the leadership group on Monday, he was the first player to put his hand up and said he made mistakes, so I am expecting a positive response if, and when, he is needed off the bench."

Howley makes five other changes with wing Liam Williams, scrum-half Gareth Davies, tighthead Tomas Francis, lock Alun Wyn Jones and flanker Sam Warburton coming into the XV.

Warburton starts at blindside flanker with loosehead Gethin Jenkins retaining the captaincy while Newport Gwent Dragons lock Cory Hill keeps his spot among the replacements.

The 24-year-old added energy when making his Test debut against the Wallabies as a sub for the Ospreys' Bradley Davies, who misses out on the 23 through injury.