Rarely can one player have affected the fortunes of his team so much as Lionel Messi.

The No. 10 is absolutely key to both club and country and it’s folly to suggest otherwise.

In many respects, both Barcelona and Argentina are a Jekyll and Hyde side, as the most recent two fixtures have proved.

Spain would probably still have had enough in their armoury to overcome La Albiceleste, but it certainly wouldn’t have been anywhere close to the 6-1 annihilation had Messi been in situ.

And Barca owe him a huge debt of gratitude for inspiring their underperforming troops to come back and claim an unlikely draw against Sevilla, given they were still 2-0 down with three minutes left.

An injury kept him out of both of Argentina’s matches, and Ernesto Valverde even admitted in his post-match news conference that Messi was still in pain during his 30-minute cameo in Andalusia.

Given how crucial he was to Barcelona maintaining their epic unbeaten record — just one more game without losing will see them tie the all-time record in La Liga — Valverde obviously considered it a risk worth taking.

Just how good or bad a decision that is will only be seen over the coming days and weeks.

The Catalans simply can’t afford to have Messi missing at this late stage and with every trophy still in play, but the player himself won’t want to risk it all for his club and then miss out on his last ever World Cup in Russia.

Either way, the effect his presence had at the Estadio Ramon Sanchez Pizjuan was palpable. For a start, a hush descended on the stadium when Messi was sent out to warm up at the start of the second half.

Within three minutes of his introduction he had set up three chances, in marked contrast to the previous 60 minutes when his team had been under the cosh for the most part.

Vincenzo Montella’s defence, polished and stoic until then, looked alarmed and ill at ease.

It would eventually force the coach into bringing on Guido Pizarro to play a double pivot with the excellent Steven N’Zonzi, but as the clock ticked down, and with the hosts having wasted at least half a dozen gilt-edged chances, Barca, and Messi, seized their moment.

An acrobatic finish from Luis Suarez gave them hope, but it was Messi’s pinpoint low-drive just 55 seconds later which was the defining moment.

With Roma arriving at the Camp Nou on Wednesday for the first leg of the Champions League quarter final, there’s little point in asking if ‘Messidependence’ is still a thing.

The question was emphatically answered in half an hour on Saturday night.