Farrell thrilled with versatile Ireland after patched-up side beat Scotland
Ireland, who have won the Triple Crown and are on course for a Grand Slam, go into the final weekend of the competition with a four point lead in the table over second-placed France and a home game to come against a struggling England side that could be led by Farrell's son Owen.
How many of his starting XV from Sunday's win will be fit remains to be seen after number eight Caelan Doris, lock Iain Henderson, hookers Dan Sheehan and Ronan Kelleher and centre Gary Ringrose had to leave the field.
"That was an amazing test match," Farrell told reporters. "A bit of organised chaos at half time, but everyone had a smile on their face. Scotland probably didn't know what was going on second half at hooker!
"It was a monumental effort but that's what these boys expect of each other. They've earned the right to take it to the last weekend."
With prop Cian Healy taking over at hooker, flanker Josh Van der Flier had the unfamiliar role of throwing in at the lineout, and after an early wobble, found his radar.
"It was immense from Josh. The lads can do anything at this moment in time – how we looked after each other was the most impressive thing.
"We'll go again, we'll have a good squad. If we get any more injuries in the week we might have to have a look at Old Belvedere Under-12s," Farrell joked.
"We'll lick our wounds. England will be dangerous, but it'll be one hell of a weekend on St Patrick's Day."