Mariano Rivera spent Thursday night's Yankees-Royals game at a Kansas City hospital, getting an MRI exam on his right knee.

The all-time saves leader was carted off the field at Kauffman Stadium after suffering a knee injury shagging fly balls during batting practice.

The great closer was propped onto the back of a flatbed truck and driven off with head athletic trainer Steve Donohue riding beside him. Rivera, 42, was gingerly helped into the clubhouse and did not appear able to put pressure on his injured leg.

The club said that the preliminary diagnosis was a strained knee.

Rivera regularly shags fly balls during batting practice and has spoken about hoping to play the outfield in a game before he retires.

That didn't take long

Uber-prospect Bryce Harper joined Washington on Saturday, and was placed in the No. 7 slot in the batting order by manager Davey Johnson.

After he went 3 for 4 in the National's 5-4 victory over Arizona on Wednesday night, raising his average to .385, he walked into the clubhouse on Thursday and saw himself listed third in the order.

Harper, who is still only 19, reacted like a normal teenager, saying "cool."

Video pays off

The Dodgers' Matt Kemp said his incendiary start has been a result of watching more video to learn the tendencies of opposing pitchers.

The revelation came after a tip from coach Davey Lopes, who told Kemp he could go from all-star to elite by just spending more time looking at footage.

"I listened," said Kemp, who leads the majors in hitting (.411) and homers (12) and is second in RBIs (25).

Ouch

Pablo Sandoval has a broken hamate bone in his left hand that will require surgery, and the Giants third baseman is expected to miss four to six weeks. The big slugger had the same injury last year on the other hand.

Jurisprudence

The Washington jury in Roger Clemens' perjury trial saw physical evidence the government says will link the 11-time all-star pitcher to anabolic steroids, evidence that Clemens' lawyer has called a "mixed-up hodgepodge of garbage."

Exhibit 52C was a partially crushed Miller Lite beer can. Exhibit 52D was the FedEx box that once contained the can. Then came exhibits of gauze, tissues, syringes, cotton balls and needles, some of which were once inside the beer can, using up letters of the alphabet all the way to X.

Clemens is charged with committing perjury when he told Congress in 2008 that he had never taken steroids or human growth hormone.

Meanwhile, Barry Bonds asked a federal appeals court to toss out his felony obstruction conviction.

Bonds' lawyers filed a 70-page legal brief with the 9th U.S. Circuit Court of Appeals in San Francisco, arguing his conviction was based on a rambling and irrelevant - but truthful - answer to a grand jury question about whether his trainer ever provided him with an injectable substance.

Contact Don McKee at dmckee@phillynews.com.
This article contains information from the Associated Press.