Butler signed an Exhibit 10 deal with the Bucks on Friday, Eric Nehm of The Athletic reports.
Essengue enters his second NBA season after spending much of his rookie year recovering from shoulder surgery.
Okoro remains primarily a defense-first wing heading into his second season with Chicago.
Ament amassed 12 points (5-10 FG, 2-3 3Pt, 0-3 FT), seven rebounds, three assists, one steal and one block across 27 minutes in Saturday's 96-94 Summer League win over Philadelphia.
Ryan (rest) didn't play in Saturday's 96-94 Summer League win over the 76ers.
Jakucionis (rest) didn't play in Saturday's 96-94 Summer League win over Philadelphia.
Burries supplied 27 points (9-18 FG, 0-4 3Pt, 5-7 FT), five assists, four rebounds, one steal and one block across 28 minutes in Saturday's 96-94 Summer League win over the 76ers.
Sellers accumulated 17 points (6-12 FG, 3-8 3Pt, 1-1 FT), two rebounds, one assist and two steals over 26 minutes during Friday's 100-91 Las Vegas Summer League loss to the Cavs.
Atwell logged 22 points (8-10 FG, 6-7 3Pt), two rebounds, one assist and two blocks over 27 minutes during Friday's 100-91 Summer League loss to the Cavaliers.
Wilson (rest) is out for Friday's Las Vegas Summer League finale versus the Cavs, K.C. Johnson of Chicago Sports Network reports.
