The Argentina coach visited Barcelona for the Liga game against Betis on Sunday and saw his star player make the difference with a fine cameo from the bench
The 25-year-old started Sunday's encounter from the bench as he continues his recovery from a hamstring injury, but single-handedly swung the match in Barca's favour after coming off the bench around the hour mark.
"Messi scored two goals and could have scored more," Sabella told Barca TV.
"Although Barca had done enough to deserve the win, it was not an easy match. But Messi is the kind of player who can change everything when he comes on."
The forward came close to netting a hat-trick in the closing stages of the game and was visibly frustrated with himself after missing a chance to make it 5-2 for the hosts.
"That’s what the greatest players are like," Sabella explained. "They get annoyed about things that wouldn’t bother other players."
Messi has scored an impressive 46 goals in 31 La Liga appearances so far this season.