So right now the safety depth chart is this:
With both Walker and Earl trying to come back from major knee injuries, McCree could end up as the de facto backup for both safety spots, with either Burns or Lord making the squad almost strictly as special teams performers. If Burns wins the job, Lord would surely be put on the practice squad. If Lord wins the job, I don't know if Burns would be eligible for the practice squad or not. The following is part of Burns bio on the main page.
PRO: Aggressive safety with good size and speed…played in one game for the Texans last season after initially being waived in training camp…also spent time on Oakland’s practice squad…originally drafted by the Texans in the seventh round (217th overall) of the 2003 NFL Draft.
2003: Saw action in one game for Houston…waived by the Texans on 8/25…signed by the Texans on 12/2…inactive at Jacksonville (12/7), at Tampa Bay (12/14) and versus Tennessee (12/21)…made NFL debut in season finale against Indianapolis (12/28), recording one special teams tackle.
Burns was on the Texans squad for about a month, playing in one game. I don't know how long he was on Oakland's practice squad. I don't know if he would be eligible to be on the practice squad again this year or not.
Anyway, the backup for strong safety could be up in the air if both Walker and Earl aren't recovered enough from last year's injuries. Lord probably needs a year of practice before he gets put in the defensive secondary. Burns could end up making the squad by default, being the only option available.