This team needs a Nomar-esque trade to wake them up. I am looking at you, Dustin.
As RedOctober pointed out above, Nomahhhh wasn't dealt to be a shot in the arm, but rather because he was underperforming, miserable, and was being painted (inaccurately or otherwise) as a malcontent in the locker room. Dustin Pedroia is exactly zero of those things (his misery is more surliness than anything else). There is no one else on the team that can even be remotely compared to Nomar Garciaparra. If they deal one of their "big name" players (which is really the only comp to Nomar you can make), it will either be a player who is playing well, which is not addition by subtraction, or a player who isn't but has a good track record or projects to be better and might just be having a tough year. Trading Dustin Pedroia would likely kill any chance this team has of making it to another postseason. Simply put, there's nobody else who has the veteran presence he has or that is the pseudo face-of-the-franchise that he has somewhat been defaulted as with Ortiz having ridden off into the sunset.
Also, even if they did have a Nomar-type player, what kind of deal are you looking to make? Nomar was dealt for Mientkiewicz and Cabera, both of whom were superior fielders at their position (and Cabrera blew Nomar's "defense" away when he arrived) but lesser players in terms of name value. Thers's also the money aspect: Nomar, despite being a superstar, was not making the superstar-level money that Manny, his own teammate, was making. Pedroia's on a good deal, but is still a solid fielder at his position; who is out there that would be better at 2B for Boston? Or do you want to install Devers at 2B? That still doesn't solve the 3B problem, either or the growing problem at 1B that stems from having a Gold Glove defender who can't move around really well and is mired in a slump at the plate and a backup who is primarily a DH (boy, does that sound familiar) and isn't particularly good at fielding his secondary position, with an added wrinkle of being incredibly streaky at the plate and having a rep for not always putting forth the best effort on a daily basis. The Nomar deal was the perfect storm: a player with a track record who still had upside for two defensive-minded players, but it still took four teams to make the whole thing happen.
What the team needs is for the players to play better, the coaches to coach better, the manager to manage better, and for those who are hurt to get better and produce when they come back. Short of that, there's no trade that can be made that will suddenly flip the offensive switch or make guys stop running into outs. I'd love Boston to get a new manager too, but, as I said in another thread, he's not getting fired in-season unless he does something truly egregious or it becomes clear that he has completely lost the clubhouse and the players are doing their own thing (which may be the case, but a spat with a TV commentator and one player assuming a public leadership role - and do we really want a player like Dustin Pedroia shying away from a leadership role? - do not constitute "clear" to me). I don't think this ownership believes in changing horses mid-stream and will evaluate his value as field manager at the end of the season like they do everything else. Letting a coach go is a little different, but that's about as far as they've shown they're willing to go and even that is little more than a public flogging. Plus they recently picked up Farrell's option (yes, they kind of had to, but that's aside from the point and obviously means they didn't want him to feel like he was managing for his job this year) and announced this big thing with him that I cannot now find on Google but sounded like something that was going to be starting next year. That may not stop them and shouldn't, but there are a lot of signs that suggest that not only does ownership like having him in the dugout but that there are big plans for him from an organizational standpoint. Firing him probably puts an end to that and they can't ask him to assume a new role mid-season. If they miss the playoffs this year or get knocked out early again as anything other than a Wild Card team, I think they have a conversation with him in the offseason about maybe shifting to a front office job, which I recall being rumored back when he was last on the hot seat and there was talk of Torey Lovullo assuming his duties. Then he got cancer and everything changed. But we can't assume they will change back now that he's healthy and the team is showing signs of trouble. We're stuck with him unless he violates the law or commits some massive baseball sin, at least until the offseason. Then we'll see.