As the 2025 MLB season progresses, fantasy baseball managers are looking for undervalued players to bolster their rosters. This week's waiver wire adds reflect strong performances from players who remain under 40% rostered in Yahoo! leagues. Daniel Schneemann, now a regular for Cleveland, is slashing .364 with four home runs since mid-April. Trent Grisham has turned skepticism into success, hitting .280 with 10 home runs on the New York Yankees. Colt Keith is rising after a slow start, showing improved contact and OBP metrics. Ryan McMahon is back on track with a .407 batting average in May, while Cade Horton, called up by the Cubs, boasts impressive Triple-A stats. Lastly, Will Vest is emerging as a reliable saves option for Detroit, having successfully converted four of five save opportunities.