Knapp had his contract selected by the Mariners on Monday.
EDGE Analysis
Knapp landed with the Mariners on a minor-league deal in late May after spending the first six weeks of the season with the Pirates. He should be in line to back up Cal Raleigh with both Tom Murphy (shoulder) and Luis Torrens (shoulder) sidelined. In 35 plate appearances with Pittsburgh, Knapp hit .129/.229/.161.