Often-injured and much-traveled wide receiver Bethel Johnson, at one time considered one of the fastest players in the league, on Monday signed a free agent contract with the Texans, team officials announced. Johnson has been either traded or released by three teams in the past 13 months, and so his addition is a gamble by the Texans, who continue to seek help at wide receiver. But even before injuries cost him some of his once-blistering speed, Johnson never caught more than 16 passes in a season, so it is doubtful he will fill the Texans' search for a complementary wideout to star receiver Andre Johnson.