The 2019 Red Sox are in a pickle. Right now, two teams in the division are better, yet the sox are coming off a title and are near the end of their window. With how many bad teams there are in the AL right now, it behooves DD to try and make a run. The sox can probably suck against the Yanks and Rays and still make a WC spot thanks to 38 games vs the awful O's and Jays. The big question coming up is will the sox rebuild and deal off some assets to make the downslope less steep, or will they fight tooth and nail to stay relevant and make the downslope incredibly painful. If DD is their GM through the end of the season, the answer is rhetorical.
This sox team needs to address 3 main weaknesses. Their rotation suddenly lacks depth. Eovaldi should return in the next 2 weeks, but he is no iron horse. Sale has finished the last 2 seasons a wounded warrior and Price has a finicky elbow that can cost him a couple weeks at a moments notice. Add in ERod's struggles and the only guy without real question marks on expectations or durability is Porcello. Adding a swing guy/5th starter isn't a bad idea here. Someone capable of piggybacking a bad start to try and hold an early deficit until the offense comes back or slots in when one of the starters invariably gets hurt would be ideal. There are only so many Shea Weber games the sox can tolerate before you completely destroy your season. You don't need someone dominant, but a veteran like Tanner Roark would do. His ERA is awesome, but the peripherals point towards a more average starter. Add in that he is on the Reds and in the final year of his deal, and he is the kind of low cost (prospect wise) acquisition that could add to your depth
Weakness number two is the bottom of the lineup. I know the sox offense isn't bad, but they are top heavy. Last year, it didn't matter because the top half was so unreal. Now with Beni becoming more above average and Betts and JDM going from MVP level to all star level, the dropoff is noticeable. When healthy, the sox run out there a lineup of Betts RF, Beni LF, JDM DH, Devers 3B, Moreland 1B, Bogey SS, Chavis 2B, Vazquez C, Bradley CF. Chavis has added a spark and Vaz has added to his ability as well, but Bradley is a graveyard offensively and Chavis is awful defensively. The sox could use a utility player to slot in when there are injuries or when someone needs a day off. Having Sale pitch helps, but using Nunez, Leon and Bradley at the bottom essentially gives away an inning. I am not advocating the sox go get an all star, but they need to get a player better than Nunez and Holt to slot into the lineup. Jose Iglesias is that guy. He has been hitting the ball, but more importantly he offers the sox an upgrade when inserted into the lineup. He would probably take over 2b and Chavis would move back to 1b with Moreland and end up being an offensive minded super utility player, which would lengthen the lineup.
The final weakness hasn't manifested entirely, but a closer would be nice for the sox. The easy call here is Colome, but with him having another year of control and being absolutely lights out to this point, I think the sox would have to part with something significant. But if you slot him into the closers role, push Barnes into the 8th inning role then use the other guys interchangeably, you can have a pretty solid back end that would serve you well.
These three additions wouldn't come cheap, and in getting them, it will put you over the final line. But having them available will significantly increase your depth and make your team formidable through injury or rest