We'll miss Heaslip - Schmidt
Ireland boss Schmidt hailed stand-in number eight Jordi Murphy's "workaholic" qualities, but conceded flankers Peter O'Mahony and Sean O'Brien must help guide the six-cap 23-year-old through Sunday's pivotal Dublin encounter.
British and Irish Lions loose forward Heaslip could still miss the rest of Ireland's Six Nations title defence after suffering three cracked vertebrae in his back in the 18-11 victory over France.
Leinster's Barcelona-born back-rower Murphy is the sole change to Ireland's starting line-up to face England at the Aviva Stadium, with Jack McGrath once again fending off the challenge of Cian Healy.
"We will miss Jamie Heaslip's experience to be honest; he's very much a big-game player with big-game temperament," Schmidt said. "That allows us to be a little bit more organised.
"So it's a big challenge for Peter O'Mahony and Sean O'Brien to help Jordi map his way around the pitch.
"Jordi Murphy's very quiet. He doesn't really say a lot, but he gets on with the job and with other people, and he's a workaholic around the pitch.
"He gets through a lot of work both sides of the ball, and that's important."
Schmidt admitted Ireland's management considered a total back-row re-jig to combat the absence of 70-cap Heaslip - but eventually settled on replacing the 31-year-old like-for-like with Leinster club-mate Murphy.
"We did, we talked about more changes," said the Kiwi, who conceded he weighed up throwing Iain Henderson in at blindside flanker and switch O'Mahony to number eight.
"Iain (Henderson) got a bit of a knock on his knee, and didn't train on the first day of the week.
"With the very short turnaround after that, though, we just felt that it was probably best to go with Jordi, who played there in the first Test against Argentina in the summer, and of course also played there against Italy."
British and Irish Lions prop Healy made his first Test appearance in the Valentine's Day triumph over France after tearing his hamstring in September.
The 27-year-old produced a solid cameo despite Ireland dominating the closing stages at the Aviva Stadium against Philippe Saint-Andre's side.
Schmidt said Healy was not quite yet up to full match speed after his lengthy lay-off, but insisted Leinster's McGrath has retained his starting place on merit.
"Sure, Jack has been the stand-out player at times," Schmidt said, confirming the call at loosehead came down to performance level alone.
"We did have temptation in a couple of areas, but, when it comes to players who are performing in their slot, it's pretty hard to go past them in terms of selection.
"But, that said, no-one owns a jersey.
"There's always temptation to change things up, but I think Jack has done a super job.
"He was probably the stand-out player for us against South Africa (in November), and he has played his way right through.
"I know that the coaching staff have genuine faith in him, and Cian is still very short of game time. Each time he gets game time he will keep improving.
"We had to recess our meeting this week to have a bit of spell to sort out those decisions in our own minds that we're talking about right now. It does make it a headache, albeit a welcome one."