The Navarrans have lost every game since their emphatic 3-0 win over Atletico Madrid at the end of February, a run that has seen them slide down the Primera Division table and left them just one point from the relegation zone.
Their latest chance to react comes in the form of an away match against fellow strugglers Rayo Vallecano, one point and four league places above Osasuna, but on a contrasting run of form, unbeaten in their last four matches.
Despite Osasuna's turn for the worse, Acuna is not worried.
"It's still in our own hands," he told reporters. "We are outside the relegation zone, although we are close to it, so we need to pull our socks up. We have a team that is good enough to react, to lift our heads up, work harder as a team and be stronger. We have to react, react and react."
Javi Garcia's side have shipped 13 goals in those last four matches, and Acuna stressed the importance of keeping a clean sheet against Rayo, hinting at a cautious approach against Paco Jemez's swashbuckling side.
"It's important we don't concede any goals and wait for the right time to attack," he said. "Being strong at the back allows you to at least pick up a point and not lose ground. We would take a 0-0 draw."
The Paraguayan, on-loan from Watford, also insisted there was no need to panic about the state of the team.
"It's football," he said. "One moment you're moving up the table and everything's going well, then you lose one or two games and you can't believe you're going to lose a third, then you end up losing a fourth. But we'll respond and I'm certain we're going to get out of trouble."
Forward Emiliano Armenteros is suspended for the game, while centre-back Alejandro Arribas is an injury doubt. Rayo have no fresh injury concerns after their 1-1 draw with Valladolid.