The St. Louis Cardinals are still showing signs of life this season. They entered Thursday's game against the New York Mets with a six-game winning streak and led the National League wild card race.The trade deadline is going to be interesting for them. They have a lot of trade candidates, but it's hard to justify selling when the Cardinals are in playoff position.If they do sell, the obvious trade candidates are Lars Nootbaar, Dustin May and JoJo Romero. However, there are a few other players that could bring back strong hauls if selling is the route they decide to go.Riley O'BrienJun 7, 2026; St. Louis, Missouri, USA; St. Louis Cardinals pitcher Riley O'Brien (61) pitches against the Cincinnati Reds during the ninth inning at Busch Stadium. Mandatory Credit: Jeff Curry-Imagn Images | Jeff Curry-Imagn ImagesRiley O'Brien was off to a hot start this season before the month of May, but after a rough stretch last month, he appears to have turned things around a little bit. The 31-year-old right-hander has recorded 17 saves and posted a 3.68 ERA.He is an under-the-radar trade candidate because of his contract status. May and Romero are on expiring deals, while O'Brien has four years of club control remaining. But that could enhance his value a little bit if the Cardinals sell.That could lead to them bringing back a couple of strong prospects for the right-hander and set them up well for the future. Relievers are volatile, so trading O'Brien while he is at his best would certainly make sense if the Cardinals don't believe they have a World Series contender this year. In all likelihood, they don't anyway, even with their hot start.Ryne StanekApr 29, 2026; Pittsburgh, Pennsylvania, USA; St. Louis Cardinals relief pitcher Ryne Stanek (55) pitches against the Pittsburgh Pirates during the seventh inning at PNC Park. Mandatory Credit: Charles LeClaire-Imagn Images | Charles LeClaire-Imagn ImagesStanek, a St. Louis native, got off to a tough start this season, but after struggling in April, he has turned things around, and he is another arm that is in the final year of his contract.He was a World Series champion with the Astros in 2022 and has been in the major leagues since 2017. Any contending team could show interest in him as a veteran bullpen piece. The haul wouldn't be as big, given that he has posted a 4.85 ERA.He has a club option for 2027, but that could help his value some, as teams in need of bullpen help could just pick that option up to have a role set for next season. There is merit to potentially putting him on the trade block, but a lot depends on where the Cardinals are in the standings by the August 3 deadline.Add us as a preferred source on GoogleFollow