Former Roosters star Shaun Kenny-Dowall has escaped conviction for possessing cocaine, after making the "monumental mistake" of accepting a small amount of the drug at Sydney's Ivy nightclub.

Kenny-Dowall appeared in Downing Centre Local Court on Tuesday, and pleaded guilty to possessing 0.29 grams of cocaine.

Tough times: Former Sydney Roosters player Shaun Kenny-Dowall leaves Downing Centre Court after pleading guilty of drug possession. Credit:Daniel Munoz

Defence solicitor Bryan Wrench told the court the 29-year-old underwent urine and hair testing soon after he was caught with a resealable bag of cocaine on May 5, proving he did not take the drug, and had not used drugs in previous weeks.

"It still doesn't excuse what he did, but this is a case where we can say it's a one-off," Mr Wrench said.