CHICAGO -- Major League Baseball has extended Chicago Cubs shortstop Addison Russell's administrative leave until Sunday, a source confirmed on Thursday.

Russell, 24, was placed on paid leave last Friday after his ex-wife posted a blog detailing abuse during their short marriage, including physical abuse. Until she linked to the blog on Instagram, his ex-wife had not been cooperating in baseball's investigation, which was opened last season when she left Russell. A source confirms she is cooperating now.

Under the collective bargaining agreement, a player can be put on paid administrative leave for seven days, which can be extended for up to another week. In this case, the leave coincides with the end of the regular season. The Cubs clinched a playoff berth on Wednesday night, but Russell's availability for the postseason is in question. It's possible he could be suspended or returned to the team in good standing. At that point, it would be up to the Cubs to determine if they want him on the playoff roster or not.

On Wednesday, Cubs manager Joe Maddon said he finally read the blog post which accused Russell of abuse.

"Domestic violence is horrible," Maddon said. "It absolutely is. By reading that, you feel her pain, absolutely. ... But I don't know enough about the other side. I'm waiting for the full report to come out then we all can draw a conclusion."

Ken Rosenthal, of The Athletic, first reported the extension of the administrative leave and that Russell's ex-wife was cooperating with the league.