Jennings is averaging 6.0 points and 5.5 assists for the Bucks on his first 10-day deal. The eight-year NBA veteran played for the Bucks' G-League affiliate Wisconsin Herd and in China before signing with the Bucks on March 11.
The 6-foot-1 guard also appeared in 291 games with Milwaukee from 2009-10 to 2012-13, averaging 17 points, 3.4 rebounds, 5.7 assists and 1.5 steals per game.
Jennings nearly recorded a triple-double in his first NBA game in almost a year during last week's win over the Memphis Grizzlies.
Jennings, who started the season playing for Shanxi Zhongyu in the Chinese Basketball Association, scored 16 points, notched 12 assists and grabbed eight rebounds in 24 minutes.
"It's just all the hard work I was putting in in China," Jennings said. "People don't understand, I was still hurt with my Achilles injury, so now I'm finally healthy. I was able to really just revamp my whole self, just focus on basketball and be able to just work out. So when I was in China, I just felt like I was at Oak Hill [Academy] again, just working on my game and trying to get to that level again."
Information from ESPN's Nick Friedell was used in this report.