Calvin Watkins of ESPNDallas.com reports the trade between the Dallas Cowboys and St. Louis Rams, where the Cowboys will send linebacker Bobby Carpenter to the Rams in exchange for offensive tackle Alex Barron, is now official.

According to Watkins, Barron is meeting with Cowboys owner Jerry Jones now at the team's Valley Ranch headquarters.

Neither former first-round pick (Barron was chosen 19th overall in 2005, Carpenter 18th overall the following year) are guaranteed starting roles with their new teams.

Carpenter, who has perhaps been miscast as a 3-4 inside linebacker in Dallas, will compete with Na'il Diggs for the team's starting strong-side linebacker job with veteran Na'il Diggs. Both are former Ohio State Buckeyes, as is Rams' starting middle linebacker James Laurinaitis.

Meanwhile, Barron (who SI's Peter King noted this morning has 43 false start penalties in his career) will compete with Doug Free for the starting left tackle job created by the Cowboys' release of veteran Flozell Adams earlier this off-season.

Both Carpenter and Barron are on one-year contracts. Carpenter in the final year of his rookie deal, which will pay him $1.19 million dollars this season. Late last week, Barron signing his one-year, restricted free agent tender which, barring a contract extension, would pay him $2.73 million dollars this season.