Dennis Smith Jr.
If the Milwaukee Bucks do lose Patrick Beverley, a replacement they could turn to is Dennis Smith Jr. Lillard and Smith's time together was brief, as the latter appeared in 37 games for the Portland Trail Blazers during the 2021-22 NBA season, which is obviously where Lillard spent his entire career prior to landing in Milwaukee.
Smith could be a viable Beverley replacement and backup to Lillard. Although Smith doesn't have the same reputation as Beverley does defensively, he is solid in his own right on that end. He's a pest and hounds his opponents consistently despite being just 6-foot-2. For his NBA career, he's averaged 1.2 steals per game, so he's prone to make plays on that end by staying active.
In addition to defense, it's clear that the Bucks need a boost in the athleticism department, and Smith, known for his highlight-level dunks, could certainly help them in that regard. He could certainly spice things up in transition for a team that was rather sluggish in that area last season. Along with that, he is still just 26, so he could add youth to this roster.
If the Bucks lose Beverley and could snag Smith on a cheap deal, it would be a solid move to keep the team's guard depth intact.