Six Nations 2015: Wales must be more clinical against Italy - Davies

Wales centre Jonathan Davies says the Welsh backs have to be more clinical against Italy on Saturday.

Title-chasing Wales have scored five tries in four matches and Davies says this needs to improve as they chase a big win in Rome.

"As a back line we probably haven't been as clinical or as threatening as we'd like to be," he said.

"The forwards work tirelessly for us. We need to make sure...Saturday that we take our chances."

England, Ireland and Wales are locked on six points with three wins, and England's points difference of 37 puts them top, ahead of Ireland's 33 and Wales' 12.

Wales are in action on Saturday 21 March away to Italy before Scotland host Ireland, with England round off the tournament against France at Twickenham.

Centre Scott Williams came off the bench to score a try in the 23-16 win against Ireland, and Davies believes the replacements could play a key role at the Olypic Stadium.

"Scott [Williams] for a number of years has scored some key tries and the whole bench came on and had a real emphasis and freshened things up," said Davies.

"So it's great for the squad as a whole and Saturday's going to be exactly the same.

"We are going to need 23 players who are full of energy, full of want and making sure that we get the result that we need."

Warren Gatland has made two enforced changes with Aaron Jarvis coming in at at tight-head and Rob Evans making his first start at loose-head in place of the injured Samson Lee and Gethin Jenkins.

There are four changes on the bench, with Rhys Gill, Ken Owens and Scott Andrews coming in as front row cover with hooker Richard Hibbard ruled out while Scarlets scrum-half Gareth Davies comes in for Mike Phillips.