Source: Manningham leaves Giants for 49ers

Mario Manningham could be catching passes from a Manning in 2012, but it won't be Eli. The free-agent receiver, who spent the last four years with the Giants, agreed to terms on a two-year deal with the 49ers Saturday night, a source confirmed. Because he has yet to sign his contract, the 49ers could not confirm the addition.

Although the 49ers currently are without a starting quarterback, they are expected to re-sign free agent Alex Smith -- who visited the Dolphins Sunday -- or land Peyton Manning this week. Having a receiver such as Manningham, who would come with a scouting report from Peyton's little brother, could sweeten the situation for the future Hall of Famer as he decides whether to make San Francisco his new home.

Manningham caught only 39 passes for 525 yards in 12 games in 2011, playing through a knee injury and trying to find playing time as Hakeem Nicks and Victor Cruz emerged. In the playoffs, though, he had 13 catches for 189 yards and three touchdowns, including one against the 49ers, in four games. He also made an astounding catch on a 38-yard pass along the sideline in Super Bowl XLVI that sparked the winning drive in the fourth quarter.

The Giants did not expect Manningham to be back in 2012. At the scouting combine in February, general manager Jerry Reese already was preparing for his departure and was asked about the possible vacancy at the No. 3 receiver position.

"I think we have some good players we still want to come along," Reese said. "To name a couple, we drafted [Jerrel] Jernigan in the third round [in 2011], so we expect him to make the jump. Ramses Barden, who we drafted a couple years ago, had some injury issues. We expect him to contribute as well."

The Giants also re-signed Domenik Hixon after a second ACL injury cost him most of last season. Those three and perhaps others will compete to fill Manningham's role.

Manningham was a third-round pick of the Giants in 2008 out of Michigan (where 49ers coach Jim Harbaugh also played). His best statistical season with the Giants was 2010, when he had 60 catches for 944 yards and nine touchdowns.

Manningham visited the 49ers Thursday and left without a contract, although both sides reinforced the idea that they still could find an agreement. He visited with the Rams this weekend before agreeing with the 49ers.

The Giants and 49ers will face each other in San Francisco this season. Manningham vs. his former team is expected to be a big storyline in that game, especially if he's catching passes from the brother of his former quarterback.