A few thoughts on 49ers' latest addition

Darcel McBath played close to 15 percent of the defensive snaps for Denver when Ed Donatell was the Broncos' defensive backs coach during the 2009 and 2010 NFL seasons.

The San Francisco 49ers hope they won't need McBath that much in 2012, but with starting safety Dashon Goldson unsigned and training camp approaching, adding McBath for insurance made sense Monday.

The 49ers announced McBath's signing. McBath's familiarity with Donatell, the 49ers' second-year secondary coach, enhanced the potential for a quick assimilation.

The 26-year-old McBath, a second-round choice in 2009 and a former cornerback at Texas Tech, appeared in one game for Jacksonville last season, participating in one defensive snap. He played extensively on special teams as a rookie and showed promise on defense, only to suffer a broken arm against Indianapolis (after picking off off Peyton Manning).

Goldson has every reason to report in time for the regular season and probably sooner. Rules for franchise players prevent him from signing anything other than the one-year, $6.2 million offer San Francisco made to him to retain his rights. In the meantime, McBath gives the 49ers more manpower for practice and someone familiar to Donatell.

McBath might not stick around long, in other words.

The signing does appear to carry at least some potential. McBath was a second-round choice, so he obviously has some talent. The injury he suffered with Denver set him back (an arm injury sidelined McBath in college as well, back in 2005). Turmoil in Denver surely worked against him as well. That combination -- injury and franchise instability -- can be difficult even for veterans to overcome.