I'd say yes, yes he could. Though undersized at a generously listed 6'8" 240lbs (likely closer to 6'7"), Booker seems to have the tools to be a Brandon Bass, Udonis Haslem, or maybe even a Paul Millsap type of player. That may not sound like much, but on a team desperate for someone to step up at PF, that type of player would be welcomed.
From a statistical perspective, Booker was solid just two seasons ago averaging 8.4 ppg, 6.5 rpg, with 1.0 spg and 0.9 bpg in just 25 mpg. His career per 36 is 11.4 ppg, 9.1 rpg, 1.2 spg, and 1.1 bpg. Booker's career Player Efficiency Rating (PER), which is all the rage now, is almost exactly the league average 15.0. Cook Book's is 14.9 and I would argue with better players around him that could improve.
Which brings us to the good ole eye test. When I watch Booker play he looks solid in a role player kinda way. He generally plays with a lot of energy and hustle, plays smart and doesn't try to do too much. Seraphin on the other hand, has more size but is more of a scorer, and mostly just a somewhat limited low post scorer at that. Vesely, ideally would step up, as he has the size/athleticism combination that most teams covet, but you have to question if he is even a legitimate NBA player at this point(hopefully he is).
The comparison to Okafor comes in where we really need someone who can play defense, hustle, rebound, and do the little things that Okafor did for us. Wouldn't Booker, much like Okafor fit in with a lineup of Wall, Beal, Webster, and Nene better than Vesely and Seraphin, thus allowing Harrington to bolster the bench playing 20-25 minutes? Yes, Booker is far from a perfect solution and is injury prone. But if healthy couldn't he be this year’s version of Okafor?