In another month, the trade talk will begin in earnest and deals will be made that reshape the pennant races.
Until then, teams have to be content with what they have. For a handful of teams, however, there will be reinforcements coming from what they haven't had -- players on the disabled list returning from injury.
These players cost nothing in terms of personnel and require no stretching of payroll, yet have the ability to dramatically impact the races. In some cases, they may eliminate the need for a trade next month.
In essence, they're the equivalent of no-risk, no-cost trades.
A look at the players coming back in June and what kind of contributions can be expected:
TROT NIXON and NOMAR GARCIAPARRA:
Though the Red Sox begin June tied for the best record in baseball, only the Angels have been hit as hard by injuries. In addition to being without Nixon and Garciaparra since spring training, they've since lost third baseman (and last season's AL batting champion) Bill Mueller, DH Ellis Burks and No. 5 starter Byung-Hyun Kim.
Nixon may be the player the Sox miss most, as right field replacements Gabe Kapler and Kevin Millar have struggled. Millar hasn't hit for power (one homer since April 23) and Kapler hasn't hit period.
Originally sidelined with a herniated disc in his back, Nixon had nearly recovered from that when another setback surfaced -- a strained quadriceps. He's been playing in extended spring training games in Florida, but could soon be sent on a rehab assignment. It's expected that he'll be back by the middle of the month.
Somehow, the Sox have managed well without Garciaparra, who's battled inflammation of the right Achilles tendon. Pokey Reese has been a standout in his place at shortstop, exhibiting terrific range. Meanwhile, second baseman Mark Bellhorn -- playing Reese's customary spot -- rebounded from a slow start to knock in 24 runs in May.
Of course, the Sox will gladly welcome Garciaparra back, enabling Reese to return to second while Bellhorn sees playing time there, at third base and DH.
Garciaparra has completed two games on a rehab at Triple-A Pawtucket. He'll resume that rehab Thursday, then likely be cleared to rejoin the Sox when they begin interleague play June 7.
The Mets were naturally excited about the notion of a new middle-infield combination -- Reyes and import Kaz Matsui -- until Reyes suffered a hamstring pull in spring training.
He's been in the Mets' spring training complex in Port St. Lucie, Fla., ever since, though his recovery rate has been far slower than projected thanks to a couple of physical setbacks.
Reyes was one of the few bright spots on a moribund team in the second-half of last season. When he returns this month, it will be to a team which has become more competitive and respectable.
The tandem of Reyes and Matsui will bring athleticism and energy to the Mets, to say nothing of speed.
His return can't come fast enough, however, as after reaching .500, the Mets have dipped some of late and have resorted to playing Ty Wigginton at second base.
For a change, optimism ran high in Wrigleyville this winter, and why not: The Cubs, it was widely acknowledged, had the best starting rotation in baseball, led by co-aces Mark Prior and Kerry Wood, and buffeted by the addition of four-time Cy Young Award-winner Greg Maddux.
But a funny thing happened on the way to the NL pennant: Prior was sidelined late in spring training with Achilles' heel tendinitis and elbow soreness, while Wood has since joined him on the DL with arm problems.
Their absence helps explain how the Cubs have been caught in the NL Central quagmire, where a handful of games in the loss column separate the six teams.
Sure, the Astros have been without Andy Pettitte twice and the Cardinals have had pitching problems of their own. But put Prior back in the Cubs' rotation -- and add Wood at a later date -- and the Cubs should take off.
If there's any consolation for the Cubbies, it's two-fold: They've hung around the race without Prior and not been trampled in the standings.
Also, Prior has pitched a lot of innings at age 23, and in the long run, the two-month absence may keep him stronger down the stretch when the Cubs will need him most.
Circle this Friday -- Prior's scheduled comeback date -- as an unofficial holiday on the North Side.
Walker is old enough now (37), with a long enough injury history (he's been to the DL six times in the last nine years and hasn't played more than 143 games in a season since 1997) that he's accustomed to the recovery process.
What isn't known is what kind of impact he can make when he returns. Once one of the game's great five-tool talents, Walker is now more limited. Even with the benefit of playing in hitter-friendly Coors Field, he hit just 16 homers in 454 at-bats last season and failed to hit .300 for just the second time since 1996.
No longer a batting champion -- or an elite outfielder, for that matter -- Walker should provide a solid bat and professionalism to the Rockies' lineup. It's doubtful, however, that he can make the Rockies factors, even in the up-for-grabs NL West. As has been the case for Walker's entire time in Denver, pitching remains the sticking point.
Walker has rejected trades in the past, and his contract and health make him a risk.
What do you get the world champions with a deep, young and talent-rich starting rotation? Try one more arm, albeit one that has undergone Tommy John surgery.
He was recently clocked in the mid-90s, and with Beckett, Willis, Carl Pavano and Brad Penny, the Marlins can boast the best rotation in their division and, arguably, the second-best in the league behind a healthy Cubs staff.
The Marlins have been patient with Burnett, in part because with their pitching depth, they can afford to have him take his time. Now, they're about to reap the rewards. Let the rest of the National League beware.
Sean McAdam of the Providence (R.I.) Journal covers baseball for ESPN.com.