Veteran linebacker Clark Haggans, who was waived on Friday by the Arizona Cardinals, has reached an agreement on a contract with the San Francisco 49ers, the Bay Area News Group reported Sunday based on information from sources. However, it's uncertain whether Haggans will be eligible to play in the 49ers' season opener on Sunday in Green Bay. Haggans is facing a three-game suspension as a result of DUI conviction in June and is scheduled to have a hearing with the NFL on Wednesday, according to the Sacramento Bee. The 49ers have not confirmed the signing and terms of the agreement are not available yet. Haggans, 35, started 16 games for the Cardinals last season, when he had 3.0 sacks. He has started 104 NFL games in his career and has 46.5 sacks.