Ronald Araujo, another central defender, was also thrown into the attack as Barca sent in 54 crosses in search of an equaliser.
Busquets and Alba follow Gerard Pique in taking a salary reduction to enable their financially troubled club to register new players and fit into the league's strict financial fair play regulations.
Piqué said he has already accepted a reduction and teammates Sergio Busquets, Jordi Alba and Sergi Roberto all captains at the club are expected to do the same soon.
Lopetegui never lost in 20 games as Spain boss, but even in a flawless qualifying campaign on the field, the Madrid-Barca rivalry.
Centre-back Pique took a knock to the knee at the team's World Cup headquarters in Krasnodar in a 50-50 challenge with striker Diego Costa.
The draw in front of a sold-out 50,653 crowd preserves both sides' respective unbeaten runs dating back to Euro 2016.
Spain coach Julen Lopetegui sought Sunday to downplay the potential impact of the Catalan independence bid on his team.
Spain comfortably defeated Albania 3-0 in a match in which defender Gerard Pique received a mixed reaction from the home supporters.
Pique has been mocked for posting he stays with a picture of him and Neymar together on Barca's pre-season tour to the US.
Gerard Pique delivered Barcelona's match winner over Real Madrid on Saturday as El Clasico Miami lived up to the hype.
Neymar has scored three goals in two friendlies for Barcelona but has studiously avoided speaking to the press.
Barcelona defender Pique remains convinced that Neymar will stay at Camp Nou, but said his opinion was based on intuition.
Neymar will stay with Barcelona, according to teammate Gerard Pique, who posted a Twitter message on the striker's status.