Betis head to Real Zaragoza on Friday as one of the surprise packages of the La Liga season, but they are anxious to get back on track after suffering their second straight home loss to Mallorca before the winter break.
"We are obliged to warn that if we do not make improvements we cannot compete in the five most important months of the season," Mel said.
"We have a month ahead and there are options to improve in a number of areas. It would be nice to be stronger to fight for bigger prizes.
"After three games it may surprise you but where you are in week 18 is not a matter of chance. It is because of hard work and because you are doing things right."
Betis are hit by the injury absences of Juan Carlos Perez and Alex Martinez ahead of the trip to Zaragoza, who bounced back from a home loss to Levante by winning 2-0 at Athletic Bilbao last time out.
Zaragoza currently sit in 12th place and are still looking over their shoulder at the drop zone, with coach Manolo Jimenez expecting a stern test from Mel's in-form visitors.
Jimenez said: "Betis are tight, disciplined and can kill you on the counter attack. They are a very good team who are fighting for the Champions League. But if we are ourselves we are able to beat anyone."