Schmidt: we have to keep lead to the end
Zebo returns to full-back and Payne to the centre
Coach Joe Schmidt has conceded it would be "a shocker" were Ireland to come unstuck against Italy.
"I sense it, I'll admit it to you, I really sense it. I know we have to win this weekend," he said.
Ireland have trawled through three rounds of the Six Nations with many positives, but just two tries and one point.
Schmidt bemoaned the fine margins that have Ireland sagging second-from bottom when they could be closer to the top of the European tree.
"What you've got to do is be good enough to make sure that enough of what you control goes your way," he said.
"When those bounces don't go your way or the decisions don't go your way, you've safe guarded yourself against what would be a shocker for us not to get something on the board this weekend."
Ireland's main source of frustration must come from how they have been in the lead in all three matches and not been able to hold onto it.
"It won't be good enough to be in front after 47 minutes," he said, like they were in Twickenham.
"It won't be good enough to be in front after 60 minutes, like we were against France.
"We've got to make sure that, for each segment of the game, we keep delivering, so we don't allow them access back into the game if we get in front or we can stay really focussed on the job at hand if they get in front."
There is a solid case to be made for the long-term international development of Ian Madigan and Paddy Jackson given the injury history of Jonathan Sexton.
"One of the things you can't suddenly do though is make someone as accomplished as the player who is currently there," he said.
The retention of Sexton for Italy was influenced by the withdrawal of Eoin Reddan.
"It may be that Kieran Marmion comes on this weekend and he has Johnny there.
"I just feel that's a situation that makes Kieran Marmion's job a bit easier in his championship debut.
"There are aspects of it that we're just trying to balance, I guess."
Sexton is simply the glue that binds the team together, like two men before him.
"Paul O'Connell is finished with us. We are not suddenly going to have someone who is as good as Paul O'Connell because in a generation of players he is a standout player.
"To have those players and replace them is incredibly difficult."
Schmidt seems to have nailed his judgement to Jared Payne as the long-term successor to a certain outside centre.
"We lost Brian O'Driscoll after the Six Nations two years ago, so we had to make sure we had someone who was able to take his place.
"But, he wasn't going to be Brian O'Driscoll."
The sense is that Schmidt has invested time and energy into Payne and is unwilling to go back to the start with someone else.
"You try and develop individuals to be the best they can be and no player is exactly the same so they don't offer exactly the same things."
In fairness, there was a distinct drop-off in Ireland's advance in defence against England from Wales and France when Payne led the line.
Ireland have been competitive in all three matches and will harbour internal angst from what happened against Wales and France.
There were chances that could have been taken against England.
Overall, however, they were beaten by the better team in London.
"I think people are probably seeing evidence of it, even if the final piece of the puzzle didn't quite get placed in the right manner," said Schmidt.
"If we can keep building the puzzle through these next two games, I'm certainly enthusiastic about what the future may hold beyond that."
Ireland: S Zebo; A Trimble, J Payne, R Henshaw, K Earls; J Sexton C Murray; J McGrath, R Best (capt), M Ross, D Toner, D Ryan, CJ Stander, J van der Flier, J Heaslip.
Italy: D Odiete; L Sarto, M Campagnaro, G Garcia, M Bellini; E Padovani, G Palazzani; A Lovotti, D Giazzon, L Cittadini, G Biagi, M Fuser, F Minto, A Zanni, S Parisse (capt).
ireland v italy, tomorrow (ko 1.30), live rtÉ 2