I am going to keep my glass half full. People are saying he will compete with Ojeleye and GWill for minutes at the off the bench PF/Swing role. I agree. Jabari has been ravaged by injury but you need to put this in perspective. Even with the injuries, compare his career base stats with either Semi or Grant:
Parker 15 pts / 6 rebs / 2 Asst / 49% FG / 32% 3pt
Ojeleye 3 pts / 2 rebs / 0.5 Asst / 39% FG / 35% 3pt
GWill 4 pts / 3 rebs / 1 Asst / 42% FG / 31% 3pt
As for what has he done lately, Parker matched pretty much these career numbers last season in 32 games with Atlanta (23 starts) playing 26 min so he can still put up these numbers if healthy and if in shape (big ifs). He played pretty well for ATL for about 2.5 months last season. It is not like this was 3 years ago.
Even limited by injuries and not playing regularly, he was able to get his career numbers right up to last season, numbers you just are not going to see from either Grant or Semi. At worst, we should get a reasonably useful bench piece on par with Semi/Grant. At best, someone who can be an actual weapon off the bench.
The down side is I don't see how he could possibly be in shape. He has barely played in the last calendar year. Is there enough time for him to get in shape and get integrated (without suffering an injury)? Like I said, for now, my glass is half going to stay half full.