Chelsea midfielder Cole was a key figure for England before he suffered a knee injury in January last year, and he struggled to regain his place in the Blues' side once fit.
Three Lions boss Capello has nonetheless handed the 28-year-old the chance to book his ticket on the plane by naming him in an initial 30-man training squad.
But Brooking feels Cole, a player he managed during his brief stint as caretaker boss of West Ham, needs to impress or he will miss out when Capello settles on his final 23 next month.
"He was one of those who people thought were marginal because he hasn't rediscovered that form, Chelsea had a lot of momentum and Joe hadn't started a lot of the games," Brooking, the FA's director of football development, said.
"A year or so ago Joe would have been a certainty but he's one of those who will have to make an impact in the next two weeks because otherwise he could be one who misses out. So it's an important spell for Joe."
Brooking does feel there are still places in the squad up for grabs for some of Capello's wildcards, such as Adam Johnson, Scott Parker and Tom Huddlestone.
"There will be a lot of interesting battles," he added.
"Although you are there as a squad you don't want to be one of the seven who doesn't make the cut.
"Having watched Fabio for a couple of years he does put a lot of emphasis on what happens in training.
"He likes to try one or two things to look at players and I do think, at the moment, there are a couple of places that could go either way and he will make that decision at the end of that period."