A manhunt continues for a Moroccan national suspected to have been the driver of a van that ploughed into crowds on Barcelona's Las Ramblas.
Barca host Real Betis (1815GMT kick-off) at the club's 99,000 capacity Camp Nou to open their La Liga campaign with the country still reeling from the most deadly attack on Spanish soil in 13 years.
A manhunt continues for a Moroccan national suspected to have been the driver of a van that ploughed into crowds on Barcelona's Las Ramblas, killing 13, on Thursday.
Hours later attackers struck again in Cambrils, 120 kilometres south of Barcelona, where a car rammed into pedestrians, killing one person.
Catalonia's regional police force confirmed there would be additional officers on duty outside the Camp Nou, but encouraged supporters to attend 'calmly'.
"The recommendation is to go calmly, to be able to enjoy a game of football and that people can go reassured because the security presence is adequate for the number of people attending," said Albert Oliva, a spokesman for the Mossos d'Esquadra.
Just over 50 miles northeast of Barcelona, concrete road blocks were mounted outside Girona's Estadi Montilivi as their first ever La Liga match against Atletico Madrid passed off safely in front of a near capacity 13,500 crowd.
"They are extraordinary and lamentable circumstances," said Barcelona coach Ernesto Valverde on Saturday.
However, Valverde hoped fans wouldn't be dissuaded by security fears and show the same spirit as huge crowds that gathered in the city's central Plaza de Catalunya on Friday to chants of "not afraid".
"We are calm. Moreover, we support the reaction of the people yesterday in Plaza Catalunya that 'we are not afraid'," added Valverde.
"We have to stand up to these circumstances and the best way is by moving forward."
"We know the way the world is, we are all potentially victims at any given moment, be it going to the metro station or going to a football ground."
"But it is something you can't control and we can't hide."
With the peak summer tourism season still in full swing and thousands of tourists expected to attend for the chance to see five-time World Player of the Year Lionel Messi, Barca said the "maximum possible" security measures would be put in place to reassure fans.
"Given the increase in situations of danger, terrorism, the club have already taken measures to reinforce security," said a Barcelona club spokesperson.
"The rule is to apply the maximum possible measures, and in extraordinary situations like this, apply them much more strictly."
A minute's silence will be held before all games in Spain's first and second divisions this weekend.
Barcelona players will also wear black armbands and shirts with 'Barcelona' replacing individual names on the back.
Former Barca defender Marc Bartra, himself the victim of a terrorist attack when a bomb hit the Borussia Dortmund team bus in April, paid his respects by kissing his black armband after scoring in Dortmund's 3-0 win at Wolfsburg in the German league on Saturday.
On the field, Barca have had a dreadful start to the season as shorn of Neymar following his world record 222 million euro ($261 million) move to Paris Saint-Germain, the Catalans were swept aside 5-1 on aggregate by Real Madrid in the Spanish Super Cup.
Yet, Valverde conceded events over the past few days had put his professional problems into perspective.
"It is our job and we know tomorrow we have an important game, but it is a different day for everyone.
"It makes you reflect at times when you have problems that everything is relative. It puts things in their place and that there are far more important things than small problems."