The troubled actress' father has warned her pals not to consume alcohol when they're out with Lindsay and is worried their influence might make the recovering alcoholic's sobriety resolution waver.
Michael told the New York Daily News newspaper's Confidenti@l section: "She's absolutely fine. She's always great, she's up early every day and I'm happy that she's sober. If [her friends] care about her, they won't drink in front of her."
Lindsay - who completed a 90-day court-ordered stint in rehab this summer - was followed by Oprah Winfrey's OWN network for an eight-part series about her life after treatment, which earned her a massive $2 million pay check.
However, the 27-year-old star was spotted on a night out at Sing Sing Karaoke bar in New York City's East Village with some girlfriends - and a male model, thought to be rumored toy boy Liam Dean - on Monday.
According to Confidenti@l, Lindsay tried to start a verbal fight and refused to leave at closing time, staying until nearly 6am.
While Lindsay did not drink any alcohol herself, her friends finished an entire bottle of Jameson whiskey.