(Reuters) - Major League Baseball spring training camps heat up this week with position players joining the early reporting pitchers and catchers, warming the hearts of fans suffering in the arctic chill of a brutal winter.

The stirrings of baseball in sun-drenched Florida and Arizona provide light at the end of a frigid tunnel and an optimistic renewal that fosters hope of better days ahead.

"It's a new beginning for all of us, each year," MLB Commissioner Rob Manfred told reporters in Arizona on the joys of spring training.

Many teams opened their coffers to restock rosters, notably the Chicago White Sox, San Diego Padres, Chicago Cubs and Boston Red Sox who could change the MLB landscape.

Comebacks by key players returning from injury will also earn close attention before Opening Day on April 5.

Slugger Giancarlo Stanton of the Miami Marlins inked the largest contract ever in North American sports -- $325 million for 13 years -- but will be tested this spring after missing the end of last season after being hit in the face by a pitch.

Stanton, 25, led the National League with 37 homers and drove in 105 runs while batting .288 despite missing the final 17 games after his beaning.

After suffering facial lacerations requiring stitches, facial fractures and extensive dental damage, he is being counted on to show unflinching resolve when next he faces an opponent's 95 miles-per-hour fastball.

The Yankees are expected to attract a horde of media covering the return of slugger Alex Rodriguez after a one-year doping ban and the health of Japanese starter Masahiro Tanaka.

Tanaka has no doubts about his right elbow, believing he can handle a full workload without further complications from a torn ligament.

"I feel it's healed," Tanaka, who went 13-5 with a 2.77 ERA in his rookie campaign, said through an interpreter. "I'm confident that I can get through this season."

Texas fans pine for a bounce back from power-hitting Prince Fielder, who played just 42 games last season before he was shut down after neck surgery.

The New York Mets, meanwhile, are banking on the comeback of hard-throwing Matt Harvey, who missed last season rehabbing from elbow surgery.

Harvey, 25, was 9-5 with a 2.27 ERA and 191 strikeouts in 178.1 innings before being shut down in the 2013 season.

I saw him throw one curveball and it was stinking dynamite, enthused Mets manager Terry Collins.

(Reporting by Larry Fine in New York; Editing by Frank Pingue)