England could probably get away with playing Jermain Defoe and Daniel Sturridge at centre back against San Marino and still win on Friday. The Three Lions can be found at [1.01] to claim three points from Friday's visit.
However, while Roy Hodgson probably won't opt for this pairing despite the apparent ease of task, the manager's U-turn on Rio Ferdinand - who has since withdrawn alongside Michael Dawson to be replaced by Joleon Lescott and Steven Caulker - begs the question of just who his preferred partnership for these qualifiers is?
And not just for these qualifiers but looking ahead to Brazil 2014?
Despite performing at a consistently high level for Spurs in recent seasons, Dawson's injury-blighted career has ensured his impact on the international scene has been limited to a skimpy tally of four caps.
There is no doubt that Ferdinand has been the standout English defender in the Premier League for his club this season, and his attempted recall was no surprise at all.
In fact, it's a real necessity rather than a regression. Since John Terry's retirement, Hodgson has used five other players for England in Rio's position and two of them are doubts for these vital qualifiers.
Everton's Phil Jagielka, who started both post-Terry qualifiers, will definitely miss the upcoming games, while there are question marks over Gary Cahill's fitness after picking up a knee injury against West Ham, though he did finish the match.
Youngsters Chris Smalling and Steven Caulker have both earned involvement in recent friendlies, though Smalling has mainly filled in at right back for Manchester United this term, whereas Caulker was pencilled in for the Under-21s until Ferdinand's withdrawal.
This leaves Joleon Lescott as the only other viable alternative, though the fact that the out-of-favour Manchester City player was brought in as a replacement for Dawson indicates that he's fallen out of Hodgson's thoughts as well as Roberto Mancini's.
Despite his age of 34, Ferdinand is still England's best defender and, if he continues to play at the same level next season, he has to be included in the World Cup party should England qualify.