Provo, 24, set a school-record among tight ends at Syracuse with 92 career receptions and had the second-most receiving yards at the position (1,027). He went undrafted last season, signing with the Baltimore Ravens.
Eckerson, 25, was one of 17 offensive linemen in training camp for the Bills. The South Carolina product signed with the Bills in February.
The moves keep the Bills roster at the 90-player maximum as they are set to take the practice field again Sunday afternoon, from 2 p.m. ET to 5:10 p.m.