Barca's unbeaten start to the season was ended at Ajax in the Champions League on November 26 with a 1-0 loss at Athletic Bilbao following five days later.
That prompted numerous debates on whether Barca are on the right track under new coach Gerardo Martino but Alves remains confident.
He told Catalan newspaper El Mundo Deportivo: "We cannot doubt the work we are doing.
"If you worry about what is coming from the outside then you are lost. If doubts are left out we will continue to the top.
"The major thing is that (the negativity) should not affect the squad. We are alone."
Alves believes the storm which followed those two losses was an over-reaction.
"If we lose it's news all day," he added. "And if we lose twice rockets are thrown everywhere."
Alves believes Barca are currently the victims of their own success after a trophy-laden era, most notably in 2009 when they claimed six titles under former boss Pep Guardiola.
"What happens here is that the demand is greater each year but the opponents get better and have less to lose," he said.
"We're fine. The problem is that people want to compare us with Pep and the six cups, and that cannot be.
"The squad still has the same desire to win but every year it becomes more difficult so it's important to give value to the victories."
Former Sevilla full-back Alves is currently sidelined with a calf problem but insists he will not rush his comeback to give Barca a much-needed boost.
"I'm fine and getting better with each passing day," he said.
"It's an injury that I have to be careful with because it can worsen others, so I have to recover well and return when ready."