Still seeking to bolster a defensive front that appears undermanned and undersized, even as the start of training camp looms, the San Francisco 49ers have signed unrestricted free agent end Byron Frisch.

The much-traveled Frisch, who is joining his fourth team in as many NFL seasons, had auditioned for 49ers coaches and team officials a few weeks ago. Contract details were not immediately available, but it is likely Frisch signed a one-year contract that included a base salary of $450,000, the minimum for a veteran of his tenure.

Frisch, 26, becomes the fourth veteran free agent defensive lineman to sign with the 49ers this offseason. San Francisco earlier in the spring signed tackles D'Marco Farr, Travis Kirschke and Ross Kolodziej. Farr, a former St. Louis Rams star, was forced to end his comeback bid after two years away from the game, however, because of knee problems.

San Francisco also selected a pair of defensive linemen, tackle Anthony Adams and end Andrew Williams, in this year's draft.

A former Brigham Young standout, Frisch originally entered the league as a third-round choice of the Tennessee Titans in the 2000 draft.

He was on the Tennessee roster as a rookie but did not see action in any games. Frisch was released in 2001, played for the Dallas Cowboys that season, and then signed with the New York Giants in 2002. He has appeared in 23 games and registered 16 tackles, five sacks, one forced fumble and two passes defensed.

Given his limited playing time, Frisch has been relatively productive as a pass rusher and has always been a solid player against the run. He likely will compete for the No. 4 end spot behind starters Andre Carter and John Engelberger and top backup Sean Moran.

In a pinch, Frisch can move inside and provide some snaps at tackle, another element that might enhance his chances of earning a roster spot. San Francsico reports to training camp on July 24.