The A's used two unearned runs off Baltimore starter Andrew Cashner to beat the Orioles 3-2 on Monday night in a series opener that featured a total of 4 1/3 innings of one-hit, shutout relief by three relievers.
Ynoa, who started the season in the bullpen, has gotten little support from his mates since getting promoted to the starting staff.
The 26-year-old is winless in four starts, going 0-2 despite a 4.50 ERA that's significantly better than his 5.60 mark in nine relief appearances earlier in the season.
Ynoa has allowed just 10 earned runs over 20 innings in his four starts, but the Orioles have lost three of the four due in large part to 15 runs allowed by the bullpen in 16 innings.
Ynoa has never faced the A's.
Jimmy Yacabonis threw two shutout innings in Monday's loss, probably giving Orioles manager Brandon Hyde one fewer option in the second game of the series.
Anderson, meanwhile, watched new A's setup man Liam Hendriks and closer Blake Treinen save Mike Fiers' win on Monday with 2 1/3 innings of spotless relief.
Hendriks was pitching in the spot often reserved for struggling Lou Trivino, whose role has become unclear even though A's manager Bob Melvin discussed his situation on Sunday.
"The reason I'm reluctant to say I'd move him around the bullpen is because I haven't talked to him yet," Melvin told reporters. "But this guy is really good. He's just going through a tough stretch. Whether or not we need to give him a little break from that (setup) role, we'll discuss it internally. But he's still got good stuff."
Melvin's actions seemed to speak louder than his words on Monday, with Hendriks not only getting the call in a critical situation in the seventh inning but also being left in the game to pitch the eighth.
Anderson benefitted from a huge offensive attack when he pitched the A's to a 13-2 win at Baltimore in April. It was just his first win in four starts against the Orioles, however, who have run up a 6.00 ERA against him.
One inspired hitter Anderson will have to deal with is Orioles right fielder Trey Mancini, who had one of his team's three hits against Fiers.
Mancini will take a .309 batting average into Tuesday's game, a mark several of his teammates believe warrants more respect in All-Star balloting.
They went so far as to try to drum up more votes for their teammate at a recent home game by driving carts to the entry gates where fans often grab All-Star ballots.
On the road, it's up to Mancini to do his own public relations. His bat will have to do the talking for him.
"You don't often see players driving in golf carts to support another player," Hyde noted to reporters before Monday's game. "It speaks to what the guys feel about him."
Mancini has gone 2-for-7 (.286) in his career against Anderson.
--Field Level Media