Diaz's fastball blazing in return from Tommy John

Reliever could rejoin Rox before May; prospect Marquez sharp in 'B' game

Diaz's fastball blazing in return from Tommy John

SCOTTSDALE, Ariz. -- Anyone skipping the last two innings at Salt River Fields to beat Monday's rush-hour traffic missed the rush of seeing Rockies reliever Jairo Diaz make his first Cactus League appearance after missing all of last season following Tommy John surgery.

The righty retired the first two Cubs in the eighth before yielding five runs on four hits and a walk. He struck out one and reached 98.8 mph with his fastball.

"He hasn't pitched in 12 months," manager Bud Black said after a 9-6 loss to the Cubs. "The first two at-bats were great, and then he started elevating the fastball. By that time, their hitters were on his velocity, and he couldn't get his secondary pitches in the strike zone. He tried a couple times with the change and slider, but he had no feel for those. A Major League hitter, or a guy in big league camp, will be able to hit a fastball that's not located, regardless of the velocity."

Black originally expected Diaz to be ready in May, but after discussing the fireballer with the coaching staff, Black concedes Diaz could be ready earlier than anticipated.

"We're going to monitor him," Black said. "We like the way he's thrown as far as his stuff. His velocity seems to have come back. We're going to continue to watch his progress as he bounces back from outings. We're going to critically evaluate his slider and his changeup. But it could be before May.

Diaz fans Almora Jr.

"We've got two more weeks of Spring Training where he'll get a couple more outings. Just how he's feeling and how his overall stuff is? It's pretty good. Now we got to get him making pitches, where after the first two hitters today he did not."

Marquez pitches in 'B' game

While starter Tyler Anderson was proving his prowess against the Cubs, rotation candidate German Marquez had a strong outing in a "B" game against Minor Leaguers on the Giants.

The righty tossed five innings of two-hit ball while walking two and striking out six. He threw 69 pitches.

Top Prospects: Marquez, COL

"Today was very good because my confidence is returning," said Marquez, ranked as the Rockies' No. 4 prospect by MLBPipeline.com. "The last three outings, [my confidence] was a little bit low."

Marquez pitched quickly and efficiently, getting through four innings without a hit before yielding two in his final frame.

"Fast is my tempo," he said. "I like to be quick. Don't be on the mound."

Marquez, 22, has pitched in four Cactus League games, allowing eight earned runs over nine innings. He is one of at least three pitchers competing for two remaining rotation spots, along with Tyler Chatwood, Jon Gray and Anderson. Right-hander Jeff Hoffman (1-0, 4.76 ERA over 5 2/3 innings) and Harrison Musgrave (1-0, 3.27 over 11 innings) are the other prime contenders.

"To me, every game is an opportunity, so I [pitch] like this is my last game," Marquez said, noting that his focus in the remaining two weeks is improving his command.

Owen Perkins is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.