Schilens signed a one-year deal, according to multiple reports.
Meanwhile, a source also told ESPN NFL Insider Adam Schefter that receiver Laurent Robinson, who was released by the Jacksonville Jaguars after just one season, is working out for Detroit on Wednesday. Robinson suffered four concussions last season but has said he is symptom-free.
Schilens, 27, played last season for the New York Jets, finishing with 28 receptions for 289 yards and two touchdowns.
Entering his sixth year, Schilens has played an entire season just once, his rookie campaign in 2008.
Burleson has recovered from a broken leg that ended his 2012 season, but he will turn 32 in August and has played all 16 games of a season only once since 2007. Broyles is recovering from his second torn ACL in as many years.
Mike Thomas is entering his first full season with the team after arriving last year via trade with the Jaguars.
Information from ESPN's Adam Schefter and ESPN.com's Kevin Seifert was used in this report.