NFL teams were allowed to agree to contracts with undrafted players immediately, a source said Monday night. Originally, the league announced that teams could not negotiate with rookie free agents until 10 a.m. ET on Tuesday. However, a change was made during the day and teams were notified they could start talking to undrafted players starting at 6 p.m. ET on Monday, the source said. NFL spokesman Greg Aiello confirmed on Twitter on Monday night that teams were allowed to negotiate with all rookies starting at 6 p.m. Monday. "Teams can negotiate with rookies tonight but not sign them until tomorrow," Aiello wrote. Read more: http://espn.go.com/nfl/story/_/id/6801695/undrafted-rookies-agree-contracts-immediately-source-says