Ireland must face South Africa, Georgia and Australia already without regular locks Iain Henderson, Dan Tuohy and Donnacha Ryan.

Schmidt has everything crossed captain Paul O’Connell, Devin Toner, Mike McCarthy and the uncapped Dave Foley ease through the second round of European fixtures unscathed.

“When you take Iain Henderson, Dan Tuohy and Donnacha Ryan out of the second row, you’re immediately starting to get a little bit skinny,” said the Ireland head coach, gearing up for next month’s Guinness series.

“Kane Douglas and Franco Van der Merwe obviously can’t be selected so take out five of eight, it doesn’t leave you with too many.

“I’m not even that good at maths – because I took five away from eight and picked four – that doesn’t even make sense!

“In saying that there’s also a little bit of excitement in that for us; Dave Foley hasn’t even filled out his frame yet.

“It’s a little bit early for him, but it gives us an opportunity to get to know Dave a little bit.

“But we’d hate to get a second row injury this weekend: that would really make things tenuous for us.”

While Munster host Saracens at Thomond Park on Friday night, Ulster welcome double European champions Toulon to Ravenhill the following afternoon.

Leinster’s Sunday trip to Castres will be no less bruising, with Schmidt not even trying to mask Ireland’s already widespread injury issues.

Long-term absentees Sean O’Brien and Cian Healy dent both set-piece stability and phase-play incision.

All told Ireland will be without 15 regular squad members through injury this autumn, with Ulster’s Paddy Jackson among those Schmidt argues are not sharp enough after enforced breaks.

The former Leinster boss said the only way to approach those absences is challenge the inexperienced replacements to make their mark.

“We’ve gone with 37 because we’re probably not going to play exactly the same team, because we probably haven’t made our minds up about some guys and some positions,” said Schmidt.

“There are a few places where we’re going to learn what the next tier are doing, and the challenge for the next tier is to become the top tier. That’s what these opportunities are for.

“There were a few guys who went into last year’s Six Nations, hadn’t been involved in the autumn Tests, and suddenly became very clearly top tier by rights because of their performances.

“That’s the opportunity and that dovetails into quite a challenge for these guys.”