ALAMEDA, Calif. - The Oakland Raiders signed free agent quarterback Christian Ponder on Friday.

Ponder, who spent the last four seasons with the Vikings, will be reunited in Oakland with new Raiders offensive co-ordinator Bill Musgrave, who worked with Ponder while serving in the same position with Minnesota from 2011 to 2013.

In Oakland, the former Vikings starter will be vying to back up Derek Carr. The Raiders also have quarterbacks Matt Schaub and Matt McGloin on the roster.

The Vikings took Ponder with the No. 12 pick in the 2011 draft.

For his career, Ponder has played in 38 games with 36 starts, throwing for 6,658 yards with 38 touchdowns and 36 interceptions.

Ponder had his best season in 2012, when he started all 16 games and led Minnesota to a playoff berth.

Earlier Friday, the Raiders signed free agent cornerback James Dockery and punter Steven Clark.

Dockery spent the past three seasons with the Carolina Panthers. He was with the Cleveland Browns, who signed him as an undrafted free agent out of Oregon State, in 2011.

Dockery has appeared in 31 games with two starts during his career. He has 30 tackles and two passes defenced.

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