Mark Berman of Fox 26 in Houston is reporting that Texans defensive tackle Travis Johnson underwent hernia surgery three weeks ago.
Johnson, who is in a contract year, has been bothered by injuries during OTAs and minicamp.
Deljuan Robinson, bolstered by a strong regular season finish last year, has been taking first team reps at the position formerly held by Johnson.
No timetable has been set for Johnson's return although Berman mentions that Johnson could be placed on the Physically Unable to Perform (PUP) list during camp.
I'm assuming that means 'Active PUP,' which is different from reserve PUP in that a player can come off Active PUP at any time during camp. However, while on Active PUP, the player takes up a roster spot.
Reserve PUP is determined at the beginning of the regular season and if a player is placed on Reserve PUP (as was Dunta Robinson last year) the player does not take up a roster spot but has to sit out the first six weeks of the season.