Monday is the first day of the workweek and the last day of the month. Tuesday could very well bring May flowers in the Major Leagues -- especially if you're the Nationals or the Angels or one of the countless fans who's been waiting patiently for the big league arrivals of Bryce Harper and Mike Trout.

That's the big story for the week to come, and if the prospect experts and prognosticators are correct, maybe the decade to come.

Harper and Trout, of course, arrived in The Show on Saturday.

Harper, the 19-year-old wunderkind with the vicious home-run swing, five-tool skill set and penchant for creative eye black, took the Washington roster space of disabled-list-bound Ryan Zimmerman. For the time being, he's going to get his at-bats. In his debut on Saturday, he went 1-for-3 with a double, one RBI and a great throw to home that beat Dodgers utility man Jerry Hairston Jr. but was bobbled by catcher Wilson Ramos, allowing Hairston to score. On Sunday, Harper went 1-for-3 with a single and a walk and a good catch in center field.

"He is going out there to compete and play the game the right way," Nationals ace Stephen Strasburg said. "He plays hard. That's what you are going to get from him day in and day out."

Trout, who's all of 20, arrived for a second tour of duty with the Angels following the release of Bobby Abreu and quickly annexed Mike Scioscia's leadoff spot. The Angels have been slumping and are hoping that Trout will be the spark they need to get their team to perform up to preseason expectations. Trout went 0-for-4 in his 2012 debut Saturday night. On Sunday, he led off and went 0-for-3.

"It's a lot to put on a kid to say he's going to be a difference-maker right away," Angels manager Mike Scioscia said. "But eventually he's going to be a real force."

This week will offer fans the first chance to see the heralded pair endure the day-to-day grind of a regular season. It should be fun.

Elsewhere in the Majors, there's a lot more to look forward to this week, and one big storyline is the sudden resurgence of the recently embattled Boston Red Sox.

Boston had won six in a row, with all six victories coming in the aftermath of blowing a 9-1 lead to the Yankees on April 21. That streak ended on Sunday with a 4-1 loss to the White Sox in Chicago. Nevertheless, the momentum seems to have shifted for the Red Sox, who are back at Fenway Park this week for series against Oakland and Baltimore.

"For the first couple of weeks, as the guys [struggled], especially on a team like this where everything gets overblown, overdrawn, you start pressing a little bit, trying harder," Red Sox first baseman Adrian Gonzalez said. "As the season goes and you get into the flow of things, you just stop thinking about that and do what you can. That's what these guys are doing."

Out West, everyone wants to know what Matt Kemp and the Dodgers are doing, and for good reason. Kemp blasted a walk-off home run in the 10th inning of Saturday's game, followed by another Dodger win on Sunday. Kemp is still dominating the National League and already earning chants of "MVP" from an adoring Chavez Ravine faithful. His journey continues this week on the road against the Rockies and Cubs, but he won't forget what he's been seeing at home.

"That goes back to last year," Kemp said. "It gives me goosebumps. It's definitely emotional, and it makes me play better. Keep doing that. It's always good to see Dodger Stadium filled like that. That's the Dodger Stadium I remember two or three years ago. Every Friday and Saturday, 56,000 fans. It helps a lot to have them on your side."

In the NL East, things continue to get intriguing, particularly this week.

The banged-up, 10-12 Phillies will have a chance to make up serious ground with series against division rivals Atlanta and Washington. The surprising Mets can have a say, too, with a week packed full of games against the Houston Astros and Arizona Diamondbacks.

The Phillies might get left-hander Cliff Lee back during the week. He has been out with a left oblique strain but could be ready for a weekend start against the Nationals. The southpaw hasn't pitched since tossing 10 shutout innings against the Giants on April 18.

"It's possible," Phillies general manager Ruben Amaro Jr. said. "We'd like to have him miss only a couple starts, but if he has to miss three or four starts, that's what it will be. We've got to be cautious. I don't want to have this thing blow out and miss him for a longer time."

Other injury returns would be most welcome for teams waiting on contributions from key pieces of their rosters.

If everything progresses as planned, the coming week should bring the healthy services of Allen Craig, a key World Series contributor for St. Louis last year; venerable Cubs starter Ryan Dempster; and Yankees catalyst Brett Gardner.

Tigers rotation workhorse Doug Fister, Padres slugger Carlos Quentin and D-backs spark plug and infield leader Stephen Drew should get into rehab games this week and are not far behind.