TODAY: Shields trade talks are “heating up,” FOX Sports’ Ken Rosenthal writes (Twitter links). The White Sox appear to still be involved, as the Padres have been scouting their prospects. One team (perhaps the White Sox, although that isn’t certain) has made a “compelling offer,” and two other teams are contenders to land Shields as well.

MAY 29: The Padres are fielding calls from plenty of teams for Shields and other players, tweets Heyman. Given the many moving parts, it is perhaps unsurprising to learn that a Shields trade doesn’t appear imminent.

As between the White Sox and Padres, discussions are “fluid,” reports Bruce Levine of 670 The Score. Whether a deal happens will come down to how much of Shields’ remaining $58MM each team is willing to absorb, per Levine, who adds that Anderson will not be part of this trade (Twitter link).

MAY 28: The White Sox and Padres are discussing a trade involving righty starter James Shields, and those negotiations have “significant momentum,” Dennis Lin of the San Diego Union-Tribune reports. It’s unclear whether a deal is likely to be completed soon, however. Jon Heyman of MLB Network corroborates Lin’s report that the White Sox and Padres have discussed Shields, but he notes that other teams are also in the mix (Twitter link).

The Padres initially signed Shields prior to the 2015 season as part of their ill-fated bid to build a competitive team. He posted a modestly disappointing 3.91 ERA, 9.6 K/9 and 3.6 BB/9 that year. He’s gotten somewhat better results this season, with a 3.06 ERA, although his peripherals (7.8 K/9, 3.2 BB/9) don’t suggest huge improvement.

The broader issue with Shields, perhaps, is his backloaded contract. He’s making $21MM this year and will make $21MM in each of the next two seasons, plus a $2MM buyout or a $16MM option for 2019. (He also can opt out after this season, but it seems unlikely right now that he’ll do so.) Those numbers could make trading for Shields tricky, especially given that he’s already 34, although Lin notes that the Padres would be willing to eat salary. It’s also unclear how Shields’ home-run tendencies might play in U.S. Cellular Field, a relatively homer-happy ballpark.

Nonetheless, Shields has an extremely durable arm and produces relatively consistent results, and he could help most teams, the White Sox included. The Sox have gotten brilliant performances from Chris Sale and Jose Quintana this season, and they’re likely also happy with Carlos Rodon and Mat Latos (although Latos has been shaky recently). Shields could, however, conceivably upgrade the other spot in the White Sox’ rotation, which currently belongs to Miguel Gonzalez.

As for the Padres’ potential return, ESPN’s Keith Law tweets that he recently heard the White Sox would be willing to part with shortstop prospect Tim Anderson in exchange for a mid-rotation starter. (There is, however, no specific indication that Anderson is involved in the Shields talks.) Anderson, the 17th overall pick in the 2013 draft, is batting a solid .314/.342/.408 for Triple-A Charlotte (although with 44 strikeouts against just eight walks) and is generally regarded as one of the White Sox’ best few prospects. He would appear to be a strong return for Shields, although it’s difficult to speculate on how the trade might work without knowing how much of Shields’ contract the Padres end up paying.