Having already visited with free-agent receivers Chaz Schilens and Brandon Lloyd, the 49ers are scheduled to meet with Mario Manningham on Thursday, ProFootballTalk.com reports.Manningham, who turns 27 in May, is a four-year veteran who caught 39 passes for 523 yards for the New York Giants last season. Manningham (6-foot, 185 pounds) started 12 of the 15 games in which he saw action. Victor Cruz and Hakeem Nicks were the Giants' top two receivers.In the NFC championship game, Manningham had caught one pass for 17 yards against the 49ers. That one reception was a 17-yard touchdown, which came midway through the fourth quarter on a third-and-15 play.Manningham caught six passes for 27 yards, including a 13-yard touchdown, in the regular-season matchup against the 49ers.The 49ers have three receivers under contract for next season: Michael Crabtree, Randy Moss, Kyle Williams and Joe Hastings. Moss on Monday signed a one-year, 1.75 million contract with 750,000 available in game-by-game roster bonuses and 1.5 million in incentives.