There is mutual interest between the 49ers and free-agent cornerback Nnamdi Asomugha, league sources indicated Wednesday to The 49ers are among three teams that have shown interest in Asomugha, a source said. Pro Football Talk reports there are four teams, including the Houston Texans, Denver Broncos and Arizona Cardinals. The 49ers also were involved with Asomugha two years ago before he signed a blockbuster contract with the Philadelphia Eagles. The Eagles released Asomugha on Tuesday after he struggled in two seasons after signing five-year, $60 million contract. Asomugha made $21 million in his two seasons with the Eagles. Asomugha (6-foot-2, 210 pounds) made the Pro Bowl in each of his final three seasons in Oakland before signing with the Raiders. However, Asomugha struggled with the Eagles. He intercepted four passes, and did not force or recover a fumble. Philadelphia allowed a league-worst 33 touchdown passes in 2012. Asomugha, who turns 32 in July, played collegiately at Cal and owns a home in Los Angeles. The 49ers want to add a big cornerback. The club showed interest in Miami Dolphins free-agent corner Sean Smith during the three-day legal tampering window over the weekend, according to a source.