From Comcast SportsNetSANTA CLARA, Calif. (AP) -- San Francisco 49ers placekicker David Akers said Thursday he received death threats on Twitter and closed the account.Akers received the death threats late last month, but is unsure at the number of posts directed at him because he did not go further back on his account to see how many."It was Twitter stuff. I got off there, so I won't deal with that anymore," Akers said Thursday.Once he initially saw them, he reported it to team and NFL security personnel. The 49ers said they were aware of the situation, and so was the league."I didn't go back and look any further," Akers said. "I hadn't been on there for weeks, so I didn't go back and look at any old ones after that. I don't take anything lightly. You really can't. I went through the proper people and what they felt like was safe."It was Akers last season who came to the defense of teammate Kyle Williams when he faced threats following two costly fumbles in the NFC championship game, a 20-17 overtime loss to the New York Giants.The 38-year-old Akers also revealed Thursday -- when newly signed kicker Billy Cundiff practiced alongside him in what has become a competition -- that he underwent double hernia surgery last February following his All-Pro season.Akers then went to see the same doctor in Philadelphia after a Nov. 25 game at New Orleans this season to have injections after the area flared up when he fell during practice working on kickoffs.Unlike 2011, when he made 44 of 52 field goals, Akers has been in a slump this season. He is 29 for 42 on field goals.He missed overtime kicks twice against the Rams this season, with the 49ers losing at St. Louis and tying at home. Akers had a field goal blocked in a loss at Seattle on Dec. 23 that Richard Sherman returned 90 yards for a touchdown.He missed two more wide left in a home victory against Arizona in the regular-season finale last Sunday before bouncing back to make two.Akers began the season by making a 63-yarder in a season-opening win at Green Bay in which the ball bounced off the crossbar and through the uprights."It's a game, it's a business, it's my career, but it's not who I am," Akers said of football. "I would definitely give that 63-yarder back to make the two kicks against St. Louis. People talk about my demeanor being down, listen, I take my job seriously. I feel when I miss kicks I let the team, the organization, the fans down. I take it personal."