The Diamondbacks optioned Bukauskas to Triple-A Reno on Tuesday.
Bukauskas struck out three over a scoreless inning in Saturday's spring game against the Padres.
Bukauskas will spend this spring as a reliever, though the Diamondbacks aren't closing the door on him as a starter down the line, Zach Buchanan of The Athletic reports.
Bukauskas was added to the Diamondbacks' 40-man roster Friday.
Bukauskas will be a part of the Diamondbacks' 60-man summer camp.
Bukauskas is working to better command his slider ahead of the 2020 season, Mike Rosenbaum of MLB.com reports.
Bukauskas (wrist) allowed one hit over a scoreless inning in Thursday's spring game against the Rangers.
Bukauskas (wrist) is scheduled to make his spring debut Thursday, Nick Piecoro of the Arizona Republic reports.
Bukauskas said his elbow is back to normal, but Arizona manager Torey Lovullo said the right-hander is experiencing discomfort in his wrist, Nick Piecoro of the Arizona Republic reports.
Bukauskas (elbow) will join the Diamondbacks' big-league camp, source reports.