Mattson, acquired from the Angels in the Dylan Bundy trade, has made three appearances with the Orioles and allowed three runs and three hits in three innings, with four walks and three strikeouts.
Left-hander Alexander Wells, who held the Red Sox to one run in six innings last night, was optioned to Norfolk. He wasn’t going to pitch in this series and the Orioles need an extra reliever.
Mattson’s three appearances came on May 7, July 3 and Aug. 7.
In 18 games with Norfolk, Mattson accumulated a 6.23 ERA and 1.731 WHIP over 17 1/3 innings. He walked six batters and struck out 24.
Thomas Eshelman will be first on the mound in a bullpen game. He’s made eight appearances with the Orioles, including five starts, and allowed 20 runs and 31 hits in 25 innings.
Eshelman’s last appearance on Sunday consisted of only one scoreless inning. His first outing of 2021 came in a June 18 start against the Blue Jays and he allowed one run and three hits in 4 2/3 innings. Lourdes Gurriel Jr. hit a home run.
Tyler Nevin is in left field again tonight.
Ryan Mountcastle’s 33 home runs lead all major league rookies this season. They’re tied for the ninth all-time by an American League rookie.
Of his 33 home runs this year, 14 have tied the game or given the Orioles a lead, including the last two.
Mountcastle’s 89 RBIs are the third-most by a rookie in franchise history, trailing Jim Gentile (98 in 1960) and Cal Ripken Jr. (93 in 1982).
Kelvin Gutiérrez has a career-high eight-game hitting streak. He’s batting .440 (11-for-25) during that stretch.
Pedro Severino has a career-high nine-game hitting streak, batting .353 (12-for-34) with five RBIs.
Cedric Mullins is celebrating his 27th birthday.
The Orioles have 107 losses, two fewer than the Diamondbacks. They’re 5-11 against Toronto.
Vladimir Guerrero Jr. is batting .349/.408/.857 with two doubles, 10 home runs and 20 RBIs in 16 games against the Orioles this season.
Left-hander Steven Matz is 13-7 with a 3.88 ERA and 1.350 WHIP in 28 starts over 143 2/3 innings. He’s allowed two earned runs or fewer in nine of his last 10 starts, though he worked only three innings in his most recent outing.
Matz has made three starts against the Orioles and allowed 10 earned runs (11 total) and 17 hits in 15 innings. He’s struck out 15 batters.
For the Orioles
Cedric Mullins CF
Ryan Mountcastle 1B
Austin Hays RF
Trey Mancini DH
Pedro Severino C
Kelvin Gutiérrez 3B
Tyler Nevin LF
Pat Valaika 2B
Richie Martin SS
Thomas Eshelman RHP
For the Blue Jays
George Springer CF
Marcus Semien 2B
Vladimir Guerrero Jr. DH
Bo Bichette SS
Teoscar Hernández RF
Corey Dickerson LF
Santiago Espinal 3B
Danny Jansen C
Cavan Biggio 1B
Steven Matz LHP