Week 21 waiver-wire watchers get a quartet of starter options with recent momentum and clear paths to value. Joey Wentz has flashed at the top of Atlanta’s rotation, but underlying metrics hint regression ahead, making him a pickup in short stints or favorable matchups rather than a long-term anchor. Nolan McLean just debuted for the Mets with a strong start that screamed untapped upside, especially with his plus curveball and a Triple-A track record. Jason Alexander’s August surge for Houston sits on a fine line between luck and skill, aided by a dominant changeup and a sinker that occasionally plays up in the right spots. Ryan Bergert, traded to Kansas City, has started to blend a sweeper more often, producing eye-popping strikeout runs in support of a lean arsenal that should be monitored in deeper formats. Overall, these names profile as short-term adds in mixed leagues and potential weekly streams in favorable matchups.