Marcelino García Toral admitted Real Racing Club were in a "tricky situation" after taking his first training session since replacing Miguel Ángel Portugal as coach.
The 45-year-old led the Santander outfit to a best-ever, sixth-place finish in 2007/08 before joining Real Zaragoza, but as he takes command for a second time, he is charged with staving off relegation. Racing are 16th in 20-team Spanish Liga. Marcelino's predecessor, Portugal, left the post on Tuesday.
"It's been two and a half years since I left and I honestly didn't expect to be back so soon," he said. "It's also the first time I've faced a situation like this – joining a team in the middle of a season – but I already know the place, the people and the city, which helps.
"We're in a tricky situation at the moment and we have to look at the realistic possibility that we're going to have to work a bit," he added. "But if we make our stadium a fortress and help each other we can start on the road to getting back to where we were in the past."