Yes, he did, he assisted the only goal in the game against Switzerland. So that's 50% of Argentina's goals in KO phase right there.
ARG 1-0 SUI (aet)
ARG 1-0 BEL
ARG* 0-0 NED (pens)
ARG 0-1 GER (aet)
Over the entire tournament, Messi had 5 direct goal contributions (4 goals and 1 assist; or 6 if you count his cross that led to an own-goal against Bosnia). Argentina as a whole scored 8 goals.
So while that doesn't excuse or justify Messi's subdued performances against Belgium and the Netherlands or his failure to score in the Final, it does place it more into context. also Di María's injury hurt them a lot in attack.