Jim Mallinder held back a number of high-profile players, including captain Tom Wood, Courtney Lawes, and Ben Foden, and the visitors duly went down to their heaviest ever defeat in Europe, falling 47 points short of their hosts at the Aviva Stadium.
Lancaster listed off a number of names who did make an appearance by way of explanation: Calum Clark, who he capped with England, Kieran Brookes, his tighthead at last year’s World Cup, Ken and George Pisi, and JJ Hanrahan.
“I don’t really buy the fact that Northampton did too much wrong. They put out the team they thought would be competitive. Let’s be fair, they got beaten at home too. If I was the coach, I would have made some changes. They put out what they hoped would be a competitive team. For 30-40 minutes, they were. Then the momentum changed. Jamie Gibson got sin-binned and we played well in the second-half. In Europe, you’ve got a certain squad size, haven’t you? You don’t have a whole load of players who are [ranked] 45-to-55 in your squad.
“You can’t put your academy out, can you?”
Any debate over ‘weakened’ teams is unlikely to end soon.
The Christmas period brings with it two rounds of interprovincials meetings, with the clash of Munster and Leinster at Thomond Park on Saturday the one likely to garner most interest and draw what is already confirmed as a sold-out crowd to the iconic venue.
Yet, recent encounters have been diluted by the IRFU’s player welfare policies and the reality is that a slew of high-profile names will again be missing from this Guinness PRO12 game as Leinster look ahead to the January 31 visit to Dublin of Ulster.
“I don’t think this game will be diluted,” said Lancaster. “It’s no different in England. When Ireland go into camp for the first Six Nations game, we’ve got a week off here. If you’re with Ireland, you don’t get a rest, so I understand the reasons.
“The trick on selection is to make sure, particularly at Leinster where there are so many Ireland internationals, that we are competitive in both games. That is where the selection will unfold. I am pretty sure it will be a competitive team.”
Guiding his team around the park — or the man who will hope for enough dominance up front to allow that to happen — will be Ross Byrne. Last man standing among Leinster’s four 10s, the St Michael’s graduate has followed Joey Carbery’s lead in taking the chance offered to him this season. Byrne has six games under his belt in the cockpit now, two of them Champions Cup assignments, though an appointment at a sold-out Thomond Park is likely to provide a far stiffer test than anything Northampton Saints offered this past two weekends.
“He has grown massively,” said Lancaster. “It is a very competitive position, fly-half. He’s obviously looked at Joey Carbery come in and take his opportunity. Cathal Marsh, as well, until he gets injured. Suddenly, he comes in. I’ve been really impressed with his development over the last few weeks.
“I thought his performance at the weekend was the best he’s played. I could see him building during the week. I thought he trained very well. He had very good control of the game plan, clarity in his mind about the way he was going to execute it.
“He led the team well, which is difficult for a young player, and he executed, but, there is another step coming and it’s on the 26th.”