The Argentine returned from two months out with a knee problem as a substitute in last weekend's 4-0 win over Real Madrid at the Santiago Bernabeu, before returning to the starting XI to play a starring role in Tuesday's Champions League demolition.
Messi enjoyed a brilliant performance, scoring twice, having another strike disallowed and setting up Gerard Pique's goal, but Luis Enrique has delivered an ominous warning to Barca's rivals by suggesting his star man is only just getting started following his return.
"He looked good to me but you can all see he is not 100 per cent," the coach said at his media conference ahead of Saturday's La Liga game against Real Sociedad.
"He still needs to get back into the rhythm of playing matches. For Messi he doesn't need to be 100 per cent to make a difference and he did that [against Roma] even playing at a low percentage of his potential.
"But he was a player who was out of action for two months and now he needs some time to get back into peak condition."
Messi was on a hat-trick in the Roma game but allowed strike partner Neymar to take a late penalty, which was missed and converted on the rebound by Adriano.
Luis Enrique is consistently impressed with the 28-year-old's selflessness despite being the hot favourite to win the Ballon d'Or.
"This generosity makes him even greater," added the former Celta Vigo boss.
"He is really not interested on individual awards because he is focused on what the team can do.
"That is what Barcelona is and why we are so great. We are going to win titles thanks to that kind of attitude and those performances.
"It think it is wonderful that the players have this mentality even though they are the greatest players in the world."