Days later, it's still hard to believe.
The baseball world suffered a huge bummer when the Yankees' great closer went down with a torn anterior cruciate ligament while shagging fly balls pregame in Kansas City on Thursday. The good news is that the 42-year-old all-time saves leader says he plans to come back. The bad news is that "Exit Sandman" is not the name of his famous song, but it's a reality for 2012.
Mo or no Mo, though, the new week could bring some happy returns and riveting matchups that will help take our minds away from the sadness brought on by Rivera's painful departure.
In fact, if former rotation stalwart and now-39-year-old would-be comebacker Andy Pettitte has any say in the matter, the left-hander will be back with those same Yankees this week. Yankees general manager Brian Cashman might disagree with those aspirations, but after a Minor League tuneup on Sunday, Pettitte made his wishes clear.
He wants in. As soon as possible.
"Yeah, I do," Pettitte said when asked if he felt he was ready. "I'll let [Yankees management] know what we've got going on. I feel like I'm ready. I feel like I'm ready to go up, and I think they're ready for me to come up. But I guess we'll just have to wait and see."
The same can be said for the Phillies, who have been in wait-and-see mode when it comes to one of their rotation anchors in Cliff Lee. The left-hander has been on the shelf since April 19 with a strained left oblique.
Lee threw a lengthy bullpen session Saturday morning at Nationals Park in Washington and pronounced himself good to go for a start Wednesday against the Mets.
"Everything is normal," Lee said. The same could be said for how the Nationals will feel when third baseman Ryan Zimmerman is back in their lineup.
That, too, could happen in what's shaping up to be an eventful week in Major League Baseball.
Zimmerman hasn't played since April 20 because of an inflamed right shoulder that landed him on the 15-day disabled list, but he said he felt good after a soft-toss hitting session on Saturday and batting practice on Sunday. Zimmerman is planning on returning Tuesday in Pittsburgh when the Nationals start a six-game road trip. His addition will only add to what's already been an impressive team.
Zimmerman injured the shoulder while making several diving plays at third during April, but he said he won't change the way he plays defense.
"Unless you want me to stop diving for the ball, those are things that happen," he said. "You play enough games and you are fortunate enough to be here long enough, you are going to get hurt. Unfortunately, I had to miss some time. Sometimes, you can play through it. Sometimes, you can't."
The Angels have been playing through one of baseball's most perplexing slumps. Until Sunday, their main man, Albert Pujols, hadn't hit a single home run. But the key words there are "until Sunday."
"The Machine" finally went yard Sunday, against the Blue Jays in a 4-3 Angels win. One should probably assume that from here on out, Pujols won't maintain a batting average under .200 (he enters Monday's games at .196) or have low slugging totals for very long now that he's off the big-fly schneid.
"It's a relief for him, and I'm pretty sure it's a relief for us," teammate Torii Hunter said. "We ain't gotta hear about Albert having a goose egg no more. I'm happy that he got this lifted off of him. Now he can go out there and just swing and have fun."
Throughout baseball, the coming week should bring lots of excitement in the form of intriguing matchups among the latest contenders.
The first-place Rangers head to Baltimore to meet the upstart Orioles, owners of a 19-9 record -- tops in the Major Leagues. The Mets and Phillies will lock horns in Citizens Bank Park in a traditionally intense National League East fray. The longtime-rival Giants and Dodgers will be pitted against each other in Los Angeles, while the Rays travel to the Bronx to see if they can keep their momentum going against the Yankees, who the Rays swept to open the 2012 season.
Later in the week, expect some hotly contested action from Rays-Orioles, Angels-Rangers and Braves-Cardinals as the division battles continue to form and head closer to the mid-point of May.
For Baltimore, which entered Monday with a half-game lead in the American League East after toughing out a 17-inning victory over the Red Sox on Sunday in which their designated hitter pitched them to a win, it still seems like anything's possible.
Sure, it's still early in the season, but it isn't that early, right?
"I think the thing our guys will do very quickly is realize we're getting ready to play the best team in the American League the last two years and probably playing as good as anybody in baseball," Orioles manager Buck Showalter said, referring to Tampa Bay.
"Pitching once again will be a premium if we're going to compete with them, but I'm real proud of them."