The Spaniard has only been in charge for seven matches, but is still awaiting his first win as the Baggies head coach.
Mel’s 17th placed side were thrashed 3-0 at home to Manchester United last time out, and now sit just outside the relegation zone on goal difference.
They travel to Wales having lost their previous two away games under Mel, who claims he is uncertain over his future.
“The only thing is winning against Swansea. Of course we must win,” he said.
“It is being said there are four important games but for me there is only one important game and that is to beat Swansea. My focus is on the players to improve them because this is the only way I can be sure I am going to be here for a long time.”
The former Real Betis manager only signed an 18-month contract at the Hawthorns in January, but Baggies chairman Jeremy Peace is thought to be considering replacements, having already sacked his ally Dave McDonough.
Mel added: “I am a very well-recognised head coach in Spain and obviously here I have to earn the right to be respected. The only way I know is through hard work.”