Frustration. The Yankees were feeling it, anyway. Then Marcus Stroman came off the board Sunday and for far less than the Yanks perceived the Blue Jays were requesting from them.

Toronto wanted Deivi Garcia to front a deal and the Yanks were dubious about sending their best high-level pitching prospect in a multi-player deal for Stroman, who they liked more as a quality innings-filler than a high-end option.

There are real questions around the game — not just in The Bronx — about Toronto’s return from the Mets. The general perception is that Anthony Kay tops out as a back-end starter.

There was strong feedback about Simeon Woods Richardson, but a few teams expressed concerns about arm injuries from his amateur days that the Blue Jays do not have.

Obviously, only the Blue Jays have full information on what they were offered and clearly their scouting reports are more encouraging, but the feeling among a few executives spoken to is that Toronto could have done this deal on deadline day (Wednesday), so why not push it more to see if it could raise the price? An executive from one team that could sell a starter was angered because of the potential to impact the rest of the market.

For the Yankees, it took an option away and as of Monday afternoon there was pessimism growing that they would land a starter. The perception among major league executives as of Monday afternoon was San Francisco’s Madison Bumgarner was unavailable while Cleveland’s Trevor Bauer and Arizona’s Robbie Ray were attainable, but at prices that would be difficult for most contenders to abide. The Mets still had Noah Syndergaard and Zack Wheeler, but the Yanks are always dubious the clubs could make a trade.

It is possible that to fill out innings and protect the best of their bullpen the Yankees just might obtain more pen pieces. Cincinnati’s Raisel Iglesias and the White Sox’s Alex Colome were available as the team waited to see if the surging Giants would move lefties Will Smith or Tony Watson.

As for starters, here is what the market was looking like:

1. Madison Bumgarner

The Giants were honoring their hot streak, manager Bruce Bochy’s retirement season and Bumgarner’s historic importance by probably going for it and keeping the lefty. They can make him the qualifying offer.

2. Trevor Bauer

He is the pitcher the Yankees would want the most because of the array of swing-and-miss stuff. That is even with makeup questions, which were accentuated Sunday when he heaved a baseball from the mound over the center-field fence upon being removed from a game. Think of him like Draymond Green — he often is going to put his personal stuff ahead of the team, but boy, is he talented.

Bauer is looking at a $20 million-ish contract next year, so the Indians are listening now. But since they lead the AL wild card and are pressing the Twins in the AL Central they will only trade if it does not doom this year and sets them up big time in the future.

3. Robbie Ray

He has avoided wildness of late (four walks in his last four starts, 24 ¹/₃ innings) and he has terrific stuff. But the lefty is homer/fly-ball susceptible and historically wild, both of which scare the Yankees. He can be a free agent after the 2020 season.

4. Noah Syndergaard/ Zack Wheeler

The Yankees do their work on all starters, but the New York teams have not made a major league trade since 2004 and it is hard to find someone with the Yankees who feels it will be possible now. The addition of Stroman makes Wheeler even more likely to be dealt, but the Padres, among others, have not given up on Syndergaard.

5. Mike Minor

With Stroman being dealt, Minor and Wheeler move into the most-likely-to-be-traded category among high-end starters. The Rangers lefty has a no-trade clause that includes the Yankees and indications are that is not just language in a contract but a huge barrier to a deal.

6. Zack Greinke

He is owed $64 million for 2020-21 and has a no-trade clause, and someone who knows him said, “no shot he would accept the Yankees.” It is uncertain if there is a sweet spot where he would go and the team would be able to afford him. My only guess is the Cardinals if they are able to, say, include the two years at $29 million owed Dexter Fowler to mitigate some of Greinke’s pact.

7. Matt Boyd

Most common refrain among executives: Detroit is valuing him as an ace. He is a No. 3. No deal.

8. Caleb Smith

I use Smith for a wild-card starter who could surprise in the market. Would Miami use a starter — an area in which it has some depth — to try to accumulate positional collateral for the future? Smith would bring a nice return.

Teams were trying to pry Reds ace Luis Castillo (apparently not happening) and the expectation is Tanner Roark will be dealt (not much excitement due to tepid stuff), but could Alex Wood, after making his first start of 2019 following a long IL stint because of his injured back, entice?

One executive wondered about David Price, who has three years at $96 million left at a time when Boston does not have a lot of financial versatility. There was industry talk the Red Sox might be willing to move someone big to set themselves up better now and in the near future. But when contacted, president of baseball operations Dave Dombrowski said he is hit with a lot of scenarios, but that it was highly unlikely he would trade a significant player from his 25-man roster.