Simpson was optioned to Triple-A Rochester after Sunday's 5-3 loss to the Cardinals.
Perkins (3-12) took the loss against the Guardians on Sunday, allowing one run on five hits and no walks with four strikeouts over six innings.
Herz (elbow) is expected to be activated from the 60-day injured list and start Monday's contest against the Tigers, Kyle Williams of TheBanner.com reports.
Irvin took a no-decision Sunday against the Cardinals, striking out eight while allowing two runs on three hits and no walks in 5.1 innings.
Cortes is absent from the lineup for Sunday's matchup with the Guardians.
Dion earned his first career save after retiring the only batter he faced in Saturday's 8-5 extra-innings win over the Cardinals.
Cornelio (3-2) earned the win in extra innings against the Cardinals on Saturday after allowing two unearned runs on three hits and a walk while striking out two over 1.2 innings.
Alvarez didn't factor into the decision Saturday against the Cardinals after allowing five hits and a walk while striking out eight over six scoreless innings.
Tolman was charged with a blown save after allowing one run on three hits while striking out one over one-third of an inning in Saturday's 8-5 extra-innings win over the Cardinals.
Walton went 3-for-3 with a home run, four RBI and a stolen base in Saturdays' 12-6 loss to the Guardians.
Great afternoon so I probably should just take my ball and go home, but what fun is that? Maybe I'm lava! (Project Hail Mary, which was wonderful but not that close to the book.) I'll throw a half down here just to have an interest while I wait for the second half of my parlay (Jays are in) to hopefully hit on Dricus du Plessis on Paramount+. It was either me being named Matthew or Dricus so that's kinda fun ... Dricus Severance does sound tough as heck.
Washington won 23-4 in the opener of this series. We can’t expect 23 runs again, but the Nats can score on anyone, and that includes J.T. Ginn, who has a 5.30 ERA over his last seven starts. Washington’s road OPS this month is a wacky 1.313 and its OPS vs. right-handers is nearly .900. Meanwhile, Nationals RHP Zack Little has a 1.80 ERA in two July starts and has given up six runs over his last four starts combined. The A’s simply aren’t hitting anyone right now.
