Captain Keiran Doris admits back-to-back champions Ireland must continue to improve and develop if they are to continue their recent dominance of the Guinness Six Nations.

Ireland are seeking to become the first country to win the title three years in a row since the tournament was expanded in 2000.

Interim head coach Simon Easterby will oversee this year’s title challenge after head coach Andy Farrell temporarily stepped down to focus on leading the British and Irish Lions’ tour of Australia this summer.

Leinster back-rower Doris dismissed the importance of his team being named title favorites by bookmakers and remains wary of the threat posed by rival nations ahead of their home game against England on February 1.

“I haven’t actually looked at the bookmakers,” the 26-year-old said at his Six Nations press conference in Rome on Tuesday.

“We know how competitive it is and it’s improving and preparing as much as possible. I don’t think we think about that (betting odds) too much.

“We realized that if we didn’t keep improving, someone else would take over.

“That’s how we’ve progressed and improved since the first meeting yesterday. In every game you can’t take anything for granted and that’s the great thing about this game.

“We play England at home first and it’s difficult to top that at the moment.

“In terms of our preparation and mentality, overall, it’s something that needs to develop and something that needs to improve individually and collectively. It’s an exciting prospect.”

Doris replaced Peter O’Mahony as captain in a shaky autumn series that began with a loss to New Zealand but ended with narrow wins over Argentina and Australia to end with three wins from four. At the end of the day, both sides easily defeated Fiji.

After that game, defensive coach Easterby replaced Farrell.

The 49-year-old former Ireland and Lions striker, who joined the Ireland squad in 2014, assembled his squad in Dublin on Monday and Doris has backed him to excel in his new role.

When asked about the differences between Easterby and Farrell, Doris said: “It’s hard to say because it’s just been a matter of hours so far, but over the last few years, Si has Unbelievable to us.

“He has a lot of respect from the players in how he leads our defense, who he is as a person and how he gets to work one-on-one with the players.

“You’ve seen a lot of what you look for in a manager over the past few years.

“Faz (Farrell) is obviously a big guy for us but we’ve lost guys like Johnny (Sexton) in the past.

“It’s not any one person trying to fill a void, it’s a shared responsibility. I’m sure the leadership team will take some responsibility as well. But there’s a tremendous amount of belief internally as well.”