Luiz Felipe Scolari fears that the protests against Brazil's hosting of the FIFA World Cup could harm their chances of winning the trophy.
Last year's FIFA Confederations Cup was blighted by demonstrations over the massive investment that has gone into the country's staging of the competition.
Further protests are still occurring in the South American nation, which will host the World Cup from June 12 to July 13, arguing in favour of increased social spending.
Brazil national coach Scolari has no issue with the protests but is concerned over the timing of the demonstrations.
"I think protests can happen," Scolari told Brazilian TV show Fantastico. "If they are normal, without smashing things up, then that is democracy.
"But I don't know if it's the right time.
"They are Brazil players and they have one mission. They can think, they can express themselves, they can say 'I want a better Brazil, too', but I don't want it to be something that causes problems in our environment."
When asked if the unrest could have an impact on his players, Scolari replied: "It could, big time."
Tournament authorities are thought to be concerned that demonstrators may attempt to disrupt some of the 64 World Cup games being held after protestors marched towards stadia during the Confederations Cup.
Brazil open the competition against Croatia on June 12 in Sao Paulo before taking on Mexico and Cameroon in their other Group A encounters in Fortaleza and Brasilia respectively.
|10||Neymar||27' 29' 71'|
|Coach: Luiz Felipe Scolari|
for Paulinho 63'
for Hulk 68'
for Neymar 88'
|´Where are the stars of Manchester United?´ - Queiroz hits out at Moyes and Van Gaal|
|Sneijder demands improved display from Netherlands|
|Real Madrid make €1m pledge to help refugees|
|Ings: I can learn from ´fantastic´ Sturridge|
|Ozil: Scotland won´t stop us|
|Portugal will be better than France - Santos|
|Kruse: I am 100 per cent fit|
|Mexico 3 Trinidad and Tobago 3: Herrera the hero for Ferretti´s men|
|FFA expect Tajikistan match to go ahead despite Dushanbe violence|
|Panama 0 Uruguay 1: Stuani´s late header clinches win|
|CONCACAF World Cup Qualifying Review: Jamaica stunned, Canada win|
|Argentina 7 Bolivia 0: Aguero, Messi star in rout|
|Canada 3 Belize 0: Hosts dominate in Toronto|
|Chelsea ´warehousing´ players - PFA chief|
|United States 2 Peru 1: Altidore inspires hosts´ comeback|
|Argentina 7-0 Bolivia: Aguero, Messi & Lavezzi net doubles in rout|
|Del Bosque unmoved by calls for two strikers|
|Deschamps praise for beautiful France|
|Fekir ruptures knee ligaments|
|Italy v Bulgaria: Conte warns against complacency|
|Euro 2016 Qualifiers Review: Germany top Group D, Northern Ireland edge closer|
|Low: Three points most important|
|Northern Ireland on the verge of a ´magnificent achievement´ - O´Neill|
|Scotland need something against Germany - Strachan|
|Portugal 0 France 1: Late Valbuena set-piece clinches deserved win|
|Faroe Islands 1 Northern Ireland 3: O´Neill´s men edge closer|
|Germany 3 Poland 1: Gotze sends world champions top|
|Gibraltar 0 Republic of Ireland 4: Irish hopes reignited|
|Djibouti 0 Togo 2: Saintfiet´s side make it two wins from two|
|Cyprus v Belgium: Benteke boost for Wilmots´ men|
|Roma youngster faces lengthy lay-off|
|United hit back at Perez barb over De Gea saga|
|Georgia 1 Scotland 0: Strachan´s men succumb to Tbilisi hoodoo|
|Hodgson prepared to blood new players|
|Porto invite Euro elite to help raise millions for migrants|
|Dortmund legend Dede backs Tuchel to succeed|
|Robben out for four weeks|
|Turkey v Netherlands: Terim expecting hostile atmosphere for crunch clash|
|Portugal 0-1 France: Valbuena strikes late to sink Ronaldo & Co|
|Wales v Israel: Euro 2016 beckons for Coleman´s history boys|
|Gala: No extra payment for Grosskreutz|
|Increase Bundesliga´s TV rights or be left behind - Rummenigge|
|Kane: I´m no flash in the pan|
|Perez: United showed inexperience in De Gea saga|
|Milligan: Socceroos wary of Tajikistan|
|Conte wants more players like Pelle|
|OFC World Cup Qualifying Review: Samoa to meet Tahiti in next round|
|Krychowiak stayed at Sevilla because of Emery|
|I never considered Bayern exit - Gotze|
|Balotelli ´not in good condition´, Milan must improve - Mihajlovic|
|Robben slams ´stupid´ Martins Indi|
|Robben laments injury blow|
|Euro 2016 Qualifiers Review: Bale edges Wales closer, Iceland dent Netherlands´ qualification hopes|
|De Bruyne relieved to ´boss´ Bosnia-Herzegovina|
|Blind furious after nightmare debut|
|Coleman sees shades of Charles in Bale winner|
|Conte only concerned about Italy winning|
|Mauritania v South Africa: SAFA to investigate Masilela no-show|
|AFC World Cup Qualifying Review: Qatar hit 15 in Bhutan rout|
|Belgium 3 Bosnia-Herzegovina 1: De Bruyne shines in straightforward victory|
|Cyprus 0 Wales 1: Bale winner takes Wales one step closer|
|Netherlands 0 Iceland 1: Sigurdsson winner caps difficult first game for Blind|
|Italy 1 Malta 0: Pelle spares wasteful Azzurri|
|Balotelli stars in Milan friendly win|
|Bhutan thrashed 15-0 by Qatar in qualifier|
|Rwanda v Ghana: Gyan doubt gives hosts hope|
|Tanzania v Nigeria: Enyeama out of AFCON qualifier|
|Valdes and Berahino included in Premier League squads|
|Costa Rica v Brazil: Dunga´s men return after Copa disappointment|
|Spain v Slovakia: Azpilicueta eyeing important revenge|
|Adebayor left out of Tottenham squad list for league and Europe|
|San Marino v England: Place in history books beckons for Rooney|
|Germany can cope with Reus absence - Low|
|Bayern offer aid to refugees in ´training camp´|
|BREAKING NEWS: Welbeck ruled out for months after knee surgery|
|South Korea 8 Laos 0: Son leads the way in rout|
|Australia 5 Bangladesh 0: Socceroos surge to emphatic win|
|Japan 3 Cambodia 0: Hosts pick up first qualifying win|
|Rudiger aiming to nail down Euros spot after Roma move|
|Melo happy to join Inter at last|
|Hernandez thanks Ferguson after United departure|
|Chung: AFC has compromised FIFA election|
|Wales the new best of British|
|Reus out of Germany qualifiers|
|Chile v Paraguay: Vidal missing for Copa champions|
|Ghedin: Anything is possible for Malta|
|Pogba will be worth €100m - Marotta|
|England can win Euro 2016 - Hodgson tells players|
|Conte unsure over Balotelli future|
|Argentina - Bolivia Preview: Mascherano backs 'very special' Messi|
|Portugal - France Preview: Deschamps aiming to correct mistakes|