Jim Davis/Globe Staff

With negotiations still open between the two sides, the Celtics and Rajon Rondo will have more time to work out a deal than they had originally planned.

The original Oct. 31 deadline to extend players in the fourth year of their rookie contracts was pushed back to Monday, according to league spokesman Tim Frank. Per the collective bargaining agreement, should the date of the deadline fall on a weekend or a holiday, then it would be moved to the next business day.

A memo from the league earlier in the week informed teams of the change.