The Seattle Mariners optioned starting pitcher Erik Swanson to Triple-A Tacoma on Friday. Relievers Matt Festa and Ryan Garton were also brought up from Tacoma, while reliever Zac Rosscup was designated for assignment. Swanson, the team's No. 9 prospect, struggled mightily in his last two outings and allowed eight runs on four home runs on Thursday in a loss to the Twins. He has a 1-5 record, 8.04 ERA, 24 strikeouts and five walks in 31 1/3 innings (six starts, seven games). Justus Sheffield[...]