Deal expected to be finalized Thursday

The Denver Broncos called defensive end John Engelberger and his agent, Robert Lattinville, to inform him they are trying to finalize a trade in which Engelberger goes to the Broncos and the San Francisco 49ers receive cornerback Willie Middlebrooks.

Middlebrooks, a former 49ers first-round pick, has been shopped in trade conversations for the past couple of months. There was some interest by the Miami Dolphins, but the 49ers heated up their interest in the past couple of days.

Middlebrooks, 26, started only two games during his four seasons with the Broncos. He's a big corner at 6-foot-1, 200 pounds, and is expected to fit in as the third corner in the 49ers 3-4 defense.

In acquiring Engelberger, the Broncos retain the public relations notion that they weren't unloading Middlebrooks as a disappointing draft choice. He was the 24th choice in the first round. His contract voided after this season and is scheduled to be a free agent.

Engelberger joins 16 other defensive linemen in Denver, but he comes to the team with talent. A former second-round choice who was the 35th pick in the 2000 draft, Engelberger started 58 of 78 games. The 49ers' switch to the 3-4 didn't fit Engelberger's abilities because he's a pure 4-3 defensive end.

The 49ers held off calling Engelberger until Wednesday because they wanted to investigate a domestic assault charge involving Middlebrooks that is scheduled to go to trail Oct. 11. The domestic charge involves a girlfriend.

Once they checked into the details of the case, the 49ers decided to go ahead and push to make the trade, which will be completed on Thursday.