In the latest moved aimed at upgrading the competition at tailback, the New England Patriots on Monday signed unrestricted free agent Mike Cloud, who played the first four seasons of his career with the Kansas City Chiefs.

Cloud, 27, had auditioned for the Patriots during the team's mini-camp two weeks ago, and reports indicated he performed well and would eventually be added to the roster. While financial details were not immediately available, it is believed that Cloud will get the league minimum base salary of $530,000 for a four-year veteran.

The caveat with Cloud, as reported by ESPN.com earlier this year, is that he must serve a four-game suspension at the start of the season for a violation of the NFL substance abuse policy. Cloud contended in an appeal that he accidentally ingested the banned substance Nandrolene while taking a supplement.

Despite arguing that the supplement was contaminated, and that Nandrolene was not one of the components noted on the label, the appeal was unsuccessful and the suspension was upheld. The four-game sanction was clearly a factor in diminishing the value of the former Boston College star in the free agent market.

At one point in the offseason, Cloud was close to a deal with the New York Giants, but the club backed off because of the suspension. After his workout with New England, the native of Portsmouth, R.I., told his representatives to seek a deal with the Patriots, given the opportunity he felt he would have and the club's proximity to his home.

A second-round choice of the Chiefs in the 1999 draft, Cloud has played in 56 games and has six starts. He has carried 121 times for 381 yards and four touchdowns and also has 11 catches for 89 yards. During the recent mini-camp Patriots coach Bill Belichick said that Cloud, if signed, might also be used on kickoff returns.

League rules permit Cloud to participate in all training camp functions and to play in the preseason games. The suspension takes effect with the first week of the regular season, and which point he would be placed on the league's reserved/suspended list, and return for the week of the fifth game.

The Patriots have been seeking viable backup to starter Antowain Smith for two years now and Cloud will challenge young veterans like Kevin Faulk, J.R. Redmond and Antwoine Womack for playing time.

Len Pasquarelli is a senior writer for ESPN.com.