Tynes, who has been sidelined since training camp with an injured left knee that required arthroscopic surgery, said Wednesday that the coaching staff told him last week that he will replace John Carney against the San Francisco 49ers on Sunday.
"There was a plan in place," Tynes said. "Last week was our target point. It just so happens to be this week."
Tynes, who made 23 of 27 field goal attempts last season and kicked the game-winning field goal in overtime in the NFC title game against Green Bay, hurt his knee in early August. He has been kicking in practice for the last three weeks, but coach Tom Coughlin elected to stay with the 44-year-old Carney, who has made all 12 of his field goal attempts and all 15 points after touchdown this season.
Tynes said he did not feel like a relief pitcher taking over after the starter left pitching a perfect game.
"I am just going to continue what he has done for us," Tynes said. "I have learned a lot in five weeks with him. It is going to help me with preparation and staying healthy and staying in this league. I am looking forward to doing just as well as he has."
Tynes said he had some setbacks after returning from his injury, mainly nagging muscle aches and some swelling in his knee. He said he is fine now.
"I'm very anxious just to get going. It's been a while," Tynes said. "I feel very good about where I am. I just want to keep up doing what John's done for us the previous five games. I'm looking forward to keeping that streak he has going."
Carney, who was signed days before the season opener, practiced on Wednesday. He was not in the locker room after Tynes spoke.
Coach Tom Coughlin had already addressed the media for the day before Tynes spoke.
It is likely that the Giants will keep Carney on the roster until Tynes kicks successfully in at least one game.