In an effort to break the negotiating logjam that has kept him out of training camp, first-round defensive tackle Ryan Sims will travel to Kansas City on Tuesday for face-to-face talks with Chiefs officials, ESPN.com has learned.

The sixth player selected overall, Sims is one of four first-round selections still without contract agreements, and one of two who have requested an investigation into possible collusion between the Chiefs and Vikings.

Sims will be accompanied by agent Hadley Engelhard, who said his client has packed enough clothes to stay in Kansas City and begin work, should the two sides reach an agreement. Engelhard pointed out, however, that the former North Carolina star has a return ticket home as well.

"Since we haven't been able to get this done, we felt a face-to-face meeting might be the thing to do, and it's really the last thing we can think of to try to make this happen," Engelhard said. "Our intention is to go there and try to strike an agreement. If we don't, Ryan comes home, and we're back where we started."

There have been no truly substantive discussions in recent days. Engelhard forwarded the Chiefs a new proposal on Aug. 19 but did not hear back from Kansas City officials and finally called them on Monday morning. The agent said that he "definitely made concessions" in his latest proposal. The hangup appears to be over so-called "back end" issues, principally "escalators" that would enhance the value of the contract.

In the last 12 seasons, the Chiefs have had only two first-round choices into camp on time, so the stalemate with Sims is nothing new to the franchise.

Engelhard declined to say how long he and his client will remain in Kansas City. "We're going there, in a proactive way, and in the hopes of getting a market value deal," he said.

Sims, 22, appeared in 44 games and started 33 for the Tar Heels, and had 167 tackles and 14 sacks in his college career. He was elevated to the first unit in a spring minicamp but that status is obviously in jeopardy now. In fact, coach Dick Vermeil said last week that Sims would not be prepared to start the Sept. 8 opener at Cleveland.

In addition to Sims, the unsigned first-round draft choices are cornerback Quentin Jammer of San Diego (No. 5 pick overall), offensive tackle Bryant McKinnie of Minnesota (No. 7) and Arizona defensive tackle Wendell Bryant (No. 12). Sims and McKinnie have filed papers, through the NFL Players Association, suggesting the Chiefs and Vikings may have colluded in their respective negotiations.

Len Pasquarelli is a senior writer for ESPN.com.