Clarke (1-2) allowed one run (zero earned) on one hit and one walk while striking out two across one inning, taking the loss to the Mariners on Friday.
Clarke entered the top of the 10th inning in a tied game, but the runner on second base scored on a single by Jarred Kelenic to give Seattle the lead. It was the second time in Clarke's last three appearances that he took the loss without giving up any earned runs. The 28-year-old has a 4.36 ERA and 1.45 WHIP with 39 strikeouts in 43.1 innings this season.