For at least three franchises, this offseason could have taken a very different path. When Justin Upton vetoed a trade to the Mariners, he altered the direction of Seattle, Arizona and Atlanta, at the very least. Such negated transactions make for fascinating what-if’s, and now that we are edging into the time of year when all we will read is “best shape of my career” posts, I thought we could step back and take a look at some of these.

Now, this sort of thing can be hard to nail down definitively, because it is rare that a general manager comes out and confirms the actual trade. But in many cases, we have what is widely considered to be the meat of a vetoed transaction. The Upton trade is such an instance where we have that meat of the transaction, but since we’ve talked about that deal ad nauseam, we’ll skip that one for our purposes here. Today, we’ll examine three players who vetoed deals and how things worked out for all those involved, and we’ll continue this series for at least one more post later in the week.

Vetoed trade 1: Rockies send Larry Walker to Diamondbacks for Matt Williams, David Dellucci, Erubiel Durazo and Bret Prinz

Vetoed trade 2: Rockies send Larry Walker to Rangers for Ian Kinsler and Erik Thompson

Completed trade: Rockies send Larry Walker to Cardinals for Jason Burch and players to be named later Luis Martinez and Chris Narveson

The first vetoed trade never really got close, because both Williams (family reasons) and Walker (he would not honor the Dbacks request for him to defer some of his salary) both invoked their no-trade clauses. But the second one could have greatly shifted the Rockies’ fortunes. Not only has Kinsler gone on to become one of the best second basemen in the majors for the past half decade, but Colorado also has not had received much in the way of keystone production in that timespan either. Since Kinsler debuted in 2006, he has been worth 27.5 WAR. In that same timeframe, the Rockies have tallied 10.3 WAR from their second basemen, good for third-worst in baseball. To say that the Rockies would be better off today with a middle infield duo of Kinsler and Troy Tulowitzki is a massive understatement.

For Walker, he controlled his destiny well. The Rangers won 89 games in ’04, but still finished third in their division, and they were a sub-.500 team in 2005. On the Cardinals meanwhile, he was on the final pieces to their pennant-winning puzzle, and other than the fact that he was thrown at home plate in the World Series by Manny Ramirez, Walker played well in St. Louis.

Vetoed trade: Royals send Zack Greinke to Nationals for Jordan Zimmermann, Danny Espinosa and Drew Storen

Completed trade: Royals send Zack Greinke, Yuniesky Betancourt and cash to Brewers for Lorenzo Cain, Alcides Escobar, Jeremy Jeffress and Jake Odorizzi

This is a fun one. Two years later, we know that the deal worked out well for Greinke, as he reached the playoffs and then landed a big free-agent deal. Everything eventually worked out for the Nationals as well, and they may have dodged a bullet in this deal not going through. It’s doubtful that they would have reached the postseason in 2011 with Greinke atop their rotation. Greinke was only worth 0.6 more wins than Zimmermann was in ’11, a negligible difference, and the contributions of Zimmermann, Espinosa and Storen in turning Washington into a contender have been significant. Washington would have been at a net loss in WAR on that deal in ’11 alone. The Nationals were able to get their ace a year later in Gio Gonzalez, and while they paid a good price, the deal didn’t involve as much major league talent.

For the Royals, the deal with Washington would have been better, but the deal they struck wasn’t the worst deal in the world. Escobar has turned into a nice little shortstop, Cain has a chance to be a decent regular and Odorizzi was part of the big James Shields trade. Would Kansas City prefer to have three young cost-controlled players instead? Yeah, probably, but they were still able to make land a decent deal.

On Milwaukee’s end, the team got a year and a half from Greinke, a trip to the National League Championship Series, and in the end still got a shortstop of the future in Jean Segura. So things definitely worked out for them, despite the fact that they came up short in the 2012 playoff chase.

Vetoed trade:Yankees send A.J. Burnett and cash to Angels for Bobby Abreu

Completed trade: Yankees send A.J. Burnett and cash to Pirates for Diego Moreno and Exicardo Cayones

This one really could have worked out well for the Angels. As you may recall, 2012 was not a banner year for Anaheim’s starting rotation. They finished 14th in K% and BB%, and 23rd in WAR (9.1) and FIP- (109). Burnett on the other hand, had his best season since 2009. Burnett posted a better K%, FIP- and WAR than any Angels starting pitcher last season, and would have proved a significant upgrade to their rotation. And not just for last season, either. This winter the Angels did their best to patch their rotation, but in two instances — Tommy Hanson and Jason Vargas — they had to trade away more significant pieces than they would have to land Burnett for what will likely be pitchers who are inferior to Burnett, or at least inferior to what Burnett is capable of in a good season. Hanson could be better if healthy, but if you believe Hanson — who has thrown 200 innings in just one of the last four seasons — will be healthy in 2013, then perhaps you’d also be interested in buying some lovely oceanfront property in Vermont that I have for sale.

The vetoed deal ended up working out just fine for the Yankees and Pirates however. Abreu wasn’t all the way to toasty, but his bread had definitely been placed in the toaster. For the second straight time, he failed to tally a one-win season, and his three homers in 2012 were a far cry from the 20 he hit in 2010. Not having him was a blessing in disguise for New York, who less than a week later signed Raul Ibanez, and his 19 homers, 1.1 WAR and incredible postseason performance worked out just swimmingly for the Bombers. Pittsburgh also made out well, as they received a pitcher who ended up being the clear champion of its staff once James McDonald crumbled after the all-star break. And they sent the Yankees little in return, as neither Moreno nor Cayones has popped up on any Yankees’ prospect lists that I have seen.