By Karolos Grohmann
BELO HORIZONTE, Brazil, June 20 (Reuters) - Four-times world player of the year Lionel Messi may not be deciding Argentina's team tactics but his criticism is crucial and welcome, coach Alejandro Sabella said on Friday.
Messi was critical of Argentina's first-half defensive formation in their World Cup opener against Bosnia despite a 2-1 win but those post-match comments were welcomed, Sabella said.
"I was not hurt by Leo's comment and he has said that before," the Argentine told reporters ahead of Saturday's Group F game against Iran. "He likes to play 4-3-3 with (Angel) Di Maria up front"
"They (reporters) asked him how he likes to play and he answered what he thinks in a respectful way. We respect each other, we have a very strong team spirit. It is good to have an open dialogue with my players.
"Sometimes players learn from us (coaches) and sometimes we learn from them."
Sabella surprisingly opted to play an extra defender in Hugo Campagnaro and sacrificed forward Gonzalo Higuain against World Cup debutants Bosnia and the result was a flat first half display that belied Argentine's status among the tournament favourites.
He changed tactics at halftime, with his players feeding Messi more and the Argentine scoring in the 65th to put them two goals ahead.
Sabella confirmed that would also be the way he would start against Iran, who drew 0-0 in their opener against Nigeria.
"We can all make mistakes you know. Tomorrow we will start with a 4-3-3 formation and we will take it from there. We may have to change the formation or not.
"I am the one who told Messi to go (to the news conference after the Bosnia game) and I fully trust all my players from a human and professional standpoint," the coach said.
"We have a two-way street in our dialogue because if you don't let them say what they want to say then you won't get the best out of them." (Editing by Ed Osmond)