Matt Kemp and Andre Ethier -- Dodgers:
The Dodgers managed to retain relevance for six weeks sans Kemp, but they averaged nearly a full run less per game in that span, and they hit just six home runs in the month of June (Kemp had twice that many by himself in April).
Kemp's return from a hamstring injury last Friday was a pick-me-up of the highest proportion, and that return was parlayed with Ethier making it back from an oblique strain. The Dodgers are a better and more productive team with Kemp in the lineup, and Ethier benefits most, as he'll see better pitches to hit than he did in June, when he hit .218.
With Kemp, the Dodgers can absolutely win the National League West. Without him? Well, that's much harder to imagine.
Jacoby Ellsbury, Carl Crawford, Clay Buchholz and Dustin Pedroia -- Red Sox:
To say the health issues that have hounded the Red Sox are the sole reasons the club has had such and up-and-down season is to oversimplify things. But you don't lose an Ellsbury, the reigning American League MVP Award runner-up, for basically the entire first half without ramifications, and the other assorted injuries haven't helped, either.
Fact is, the Red Sox are a talented team getting a rousing round of reinforcements at a pivotal point in the calendar. What can Crawford contribute after an abysmal 2011 and while playing with a torn elbow ligament? The answer to that question will go a long way toward determining the Red Sox's final standing. But Ellsbury is healed, Buchholz looked sharp in his return from esophagitis on Saturday and Pedroia should be back from an injured thumb on Thursday. Reliever Andrew Bailey (forearm strain) is also nearing a rehab stint.
That's the good news. The bad? Ortiz injured his Achilles on Monday night and was headed for an MRI. That's a big blow, and other injuries will crop up, as they always do. But some core pieces are being put in play, and it will be interesting to see if Boston can stay healthy enough to improve their hopes of winning the AL East.
Lance Berkman -- Cardinals:
Over the weekend, "The Big Puma" returned from knee surgery, and though Berkman is not yet starting consecutive games, manager Mike Matheny now has a roster crunch on his hands. With Berkman, Carlos Beltran and Matt Holliday in the mix, trying to find ample playing time for Allen Craig is an issue, but that's ultimately a good problem to have.
Alas, what the Cardinals needed most in the second half -- a healthy and effective return for Chris Carpenter -- isn't going to happen. So they'll have to hope a healthier lineup keeps the runs coming.
Roy Halladay -- Phillies:
Philadelphia got Chase Utley and Ryan Howard back just before the All-Star break. With Halladay, recovered from a lat strain, making his first start since May 27 on Tuesday night, the Phillies, at long last, are fielding something resembling the club that won 102 games last season.
Alas, they're fielding it in mid-July, 11 games under .500 and 10 back of a Wild Card spot. It's a monumental hole they've dug themselves, and with the trade waters brewing and Hamels and Shane Victorino both approaching free agency, it's going to be awfully interesting to see how the next couple weeks play out. The returns of Halladay, Howard and Utley are big boosts, sure, but they might be too late to stop the Phils from selling and sinking.
CC Sabathia -- Yankees:
This is a case of the rich getting richer, as the Yankees already have the best winning percentage in baseball and were relieved to see Sabathia miss only two starts after straining his groin last month. Getting the big man back atop the rotation is obviously attractive, and the extra down time might prove to be an unanticipated benefit when all is said and done. Sabathia has been such a workhorse -- pitching at least 230 innings in the regular season and logging additional time in the postseason each year from 2007-11 -- that the fresh feeling he'll take into Tuesday's start couldn't hurt.
But with Andy Pettitte out with a broken ankle until September, it would not be a shock to see the Yanks look for starting help to surround CC before the Deadline.
Colby Lewis and Alexi Ogando -- Rangers:
No club entered the year with a deeper pitching staff than the Rangers, and they've had to lean on it -- and even add to it, with the Roy Oswalt signing -- quite a bit thus far. It hasn't shown much in the standings, where the Rangers still have a nice cushion on the Angels, but the rotation has been ravaged by injuries.
Now, with Ogando back (in a relief role) and Lewis making his return to the rotation Wednesday night against the A's, Texas is back in the depth department. Neftali Feliz, out with elbow inflammation, also began his rehab work in the Minors on Monday, and he'll be stretched out as a starter. The Rangers are a terrific team that could get a good deal better in the coming weeks.
Nick Markakis -- Orioles:
The O's were in the midst of a 22-inning scoreless streak when Markakis rejoined them last Friday night. Buck Showalter was so jazzed that he slotted Markakis into the leadoff spot for the first time in his career.
Having Markakis back in the fold gives the O's a needed injection of quality at-bats, but Markakis was powerless to prevent the knee injury that forced Jason Hammel to exit Friday's start early and sent him to the surgeon's table.
It just goes to show that the injury report giveth and taketh. And when it taketh more than it giveth, maybe the trade department should be your focus.