The Argentina forward's incredible goals tally in recent years - he has netted 47, 53, 73 and 60 goals respectively in the past four seasons - has unsurprisingly stolen the limelight from the number of assists he makes for his team mates.
But he is also an important link to his fellow attackers, often dropping deep to collect the ball from a midfielder or defender before passing it on or making a trademark weaving dash towards goal.
Opponents desperately trying to thwart him are dragged out of position and that creates space for Barca's other forwards like Pedro and Alexis Sanchez or roving playmaker Cesc Fabregas.
Messi, who has not scored in three La Liga appearances this month since returning from injury, set up all three of winger Cristian Tello's goals in last week's King's Cup quarter-final, first leg at Levante.
Barca won the game 4-1 and are overwhelming favourites to advance to the semi-finals when the teams meet for the return leg at the Nou Camp on Wednesday (2100 GMT).
"Messi can do whatever he wants because he is capable of everything," Barca coach Gerardo Martino told a news conference after Sunday's 3-0 La Liga win at home to Malaga.
Messi, who has been scoring freely in the Cup and netted four against Getafe in the last 16 in a 6-0 aggregate success, set up Pedro for the second and also had a hand in the third scored by Alexis.
"He is very precise in assisting team mates and he draws the attention of opponents," added Martino, who like Messi hails from the Argentine city of Rosario.
The four-times World Player of the Year has made 148 goal assists for club and country during his career, 123 for Barcelona and 25 for Argentina, according to unofficial Twitter account @messistats.
"Messi always brings us a great deal," centre back Gerard Pique, a contemporary of the Argentine at Barca's academy, told reporters on Sunday.
"When he is not scoring he makes a lot of assists and he gives fluidity to our play," added the Spain international.
If Barca get past Levante as expected, they will play La Liga rivals Real Sociedad or third-tier Racing Santander in next month's two-legged semi-finals.
Santander are the surprise packages of this year's competition but need to overturn a 3-1 deficit when they host Sociedad on Thursday (2000) if they are to advance.
On the other side of the draw, holders Atletico Madrid take a 1-0 lead to Athletic Bilbao on Wednesday (1900) and Real Madrid, who lost 2-1 to Atletico in last year's final, have the same advantage when they host Espanyol on Tuesday (2000).
Atletico are riding high in La Liga and stayed level with Barca at the top on 54 points thanks to Sunday's 4-2 win at Rayo Vallecano, a point ahead of third-placed Real Madrid.
"We hope now to put in a good performance in Bilbao and then focus on the following week because each game takes a lot out of us and obviously we notice it," coach Diego Simeone, another Argentine, told a news conference.