Leo Cullen has overseen a flawless start to the season as Leinster lead the way on domestic and continental fronts. So impressive have been the province's performances that opponents may be left relying on complacency to level the playing field.

Speaking after the 50-21 dismantling of Northampton in Aviva Stadium, Cullen was confident his charges would have enough personal ambition to keep the foot on the pedal through Christmas.

New Ireland coach Andy Farrell has a blank canvas to work with ahead of the 2020 Six Nations and Cullen knows many of his young charges will have an eye on debuting in green.

Number 8 Caelan Doris and injured hooker Ronan Kelleher have caught the eye, while Ross Byrne, Dave Kearney and James Tracy will be keen to start afresh under Joe Schmidt's successor.

Leinster have qualified for the last eight of the Heineken Champions Cup with two games to spare and have a healthy lead at the summit of Guinness Pro14 Conference A heading into the busy festive period.

"How we manage the group now is important. We are in a good place in our pool, but need to kick on now and maximise rounds five and six then it breaks up after that," Cullen told RTE Radio's Michael Corcoran.

"All the players know what is at stake - there will be a certain squad picked," he added. "These next three weeks there will be a lot on the line for individuals. It is important for a team context to understand what produces good performances from our point of view."

Northampton have been dismissed on an aggregate score of 93-37 in the back-to-back matches, but Cullen highlighted some defensive frailties as he looked ahead to three domestic showdowns on the spin.

"We are into three massive interprovincial games in the Guinness Pro14. We have Ulster on a six-day turnaround on Friday, hopefully we get a big crowd at that one, then we are down to Thomond on the 28th and then Connacht in the RDS the week after that," he said.

"They are three great games for lots of different reasons really, obviously the interprovincial rivalry is fantastic, a great chance for a lot of our guys, there will be a fair bit of chopping and changing with all the teams to try and keep the groups healthy," added Cullen, who has overseen eight wins in eight weeks since the end of October. 

"We have talked about this block of games, 13 games, eight down now, three in the pros and rounds five and six then."

In the absence of knee injury victim Jonathan Sexton, Ross Byrne started at fly-half and contributed 11 points before a dead leg forced him off, allowing Skerries youngster Ciaran Frawley to come on for his European debut.

Cullen was impressed with the way Frawley handled himself in front of a 42,041-strong crowd, adding: "Ross, just a dead leg for him. It was great experience for Ciaran Frawley to come on in that game. It's a massive step up. He's 22 years of age. Another positive step in his progression.

"You're playing here in the Aviva. We talked about it here yesterday. To get over 40,000 to a regular-season game is brilliant. Hopefully we have a couple of big attendances during this Christmas period as well with the interprovincial games."