The 31-year-old had spent the last several weeks deputising for on-loan Spaniard Joel Robles but returned to the starting side against their Championship opponents.
He is now determined to hold on to his spot and become the first Omani to step out at Wembley Stadium in a FA Cup final.
"I've missed the last few games in the league. That was the gaffer's decision, but we have a big squad and everybody has to be ready," Al Habsi told AFP.
"This feeling (yesterday) in the semi-final was fantastic and I imagine the final will be something amazing.
"I will be the first from Oman and the Middle East to play in the final. Everyone is so happy there. I am so proud for myself and the team."