The Colombian international arrived at the Emirates Stadium in the summer after making more than 200 appearances and 500 saves for French side Nice.
Although he has to wait for his opportunity to impress in the Premier League behind Wojciech Szczesny, the 26-year-old custodian has now grabbed it with both gloves; keeping successive clean sheets against Stoke, Manchester City and Aston Villa.
Ospina's form has been recognised by Arsenal legend Jennings, who made 327 appearances for the Highbury side from 1977-85. And the 69-year-old believes he has earned the right to start against arch rivals Tottenham at the weekend.
"Who would I pick for the derby? I’m quite happy with either, but with the way Ospina has played, he’ll probably stay in," Jennings - a League Cup, FA Cup and UEFA Cup winner with Spurs - told FourFourTwo.
Ospina adds valuable experience to the Gunners' ranks, capped 49 times by his country and helping them reach the World Cup quarter-finals last year.
And Jennings feels Arsene Wenger no longer needs to search for a truly world-class goalkeeper, as the current pair provide healthy competition for the No.1 spot.
"I’ve really liked the look of Ospina in the games he has played, I’ve got no worries about him," he said.
"And Szczesny is a brilliant player as well. Arsenal are fortunate to have good competition for the place, so I wouldn’t say they need to sign anyone else."
Pat Jennings is urging local communities to recognise a #GrassrootsHero and nominate them for the 2015 Community Awards, presented by McDonald's. For more information and to nominate a club, league, coach or volunteer, click here.