Villarreal were firmly in contention at 2-1 early in the second half after Pape Gueye struck four minutes after the restart. The goal handed the visitors belief and momentum, putting the hosts under pressure despite their early advantage.
However, Comesana pointed to Flick's introduction of Pedri as the tactical turning point, suggesting the midfielder's presence restored Barcelona's control and composure.
"Pedri calmed everything down, he took the ball away from us. With Pedri the match stopped being back and forth," said Comesana, via MD.
"Barca had much longer possessions, they did not run after the ball. He filters the pass for the third goal that breaks three defensive lines, and there we give up a little. We tried but we no longer had conviction."
Ultimately, Barcelona ran out 4-1 winners, inspired by a scintillating display from Lamine Yamal. The teenager netted his first career hat-trick, repeatedly unsettling the Villarreal defence with his direct running and sharp finishing.
Barcelona were the biggest winner in Saturday's exciting La Liga action in a day where no fixture ended goalless with crucial points collected at both ends of the league table.
The UEFA Champions League round of 16 draw produced heavyweight clashes and high-stakes drama, with six Premier League clubs handed demanding tests on the road to Budapest.
FC Barcelona have been dealt a major setback after confirming that midfielder Frenkie de Jong will be sidelined for up to six weeks with a hamstring injury.
FC Barcelona defender Gerard Martin has insisted his side still believe they can produce a dramatic comeback against Atletico Madrid on Tuesday in the Copa del Rey semi-final.
