First baseman Brandon Belt
Aside from Starting Pitching, this is the other glaring need for the 2024 Pirates. After trading away Carlos Santana and Ji Man Choi, the team seems to be rolling with Alfonso Rivas and Connor Joe the rest of the way for this year. Perhaps we'll see a September call-up for Malcolm Nuñez, but unless he sets the world on fire, the Pirates will likely have to head back to the free agent market to fill first base again.
If the Pirates were truly serious about competing next year, they'd make a run at trying to sign Rhys Hoskins, but we're trying to at least be semi-realistic here. Brandon Belt is enjoying a nice bounce-back year where is slashing .254/.370/.453 with a 130 wRC+ in 84 games up to this point. His left-handed swing would fit nicely at PNC Park, and he'd bring a similar veteran leadership presence to what we saw with Santana earlier this season. He's making $9.3 million in 2023.
The Pirates would probably have to overpay for him as the free agent options for first base are quite shallow. However, "overpaying" for Belt would still be substantially less than the $20 million or so AAV you would have to give to Hoskins, and Belt isn't coming off of a significant injury either. Unlike Hoskins, I think there's a real possibility of this one actually happening. Belt seems like exactly the type of player Ben Cherington would covet to fill the need at first base, and it would definitely be a great fit.