Speaking directly about the topic for the first time since gambling-related tweets appeared on his Twitter account last week, Miami Marlins pitcher Jarred Cosart denied ever betting on baseball.

"I never have, never will bet on baseball," Cosart said Wednesday.

Tweets that appeared on Cosart's since-deleted account discussed gambling advice received from a gambling expert. They did not appear to involve baseball bets.

Cosart briefly addressed the situation last week, stating he was cooperating with Major League Baseball's investigation.

"Still following the MLB protocol. Hoping that everything gets done by Opening Day," Cosart said.

MLB spokesman Michael Teevan said the investigation is ongoing.

MLB rules prohibit players and other employees from betting on baseball games. A player who bets on a game not involving his team faces a one-year suspension, and a player who bets on or against his own team faces a lifetime ban. The commissioner, at his discretion, can discipline a player for placing other types of bets with an illegal bookmaker.

Axford's son on mend

Colorado Rockies reliever John Axford's 2-year-old son is improving following a rattlesnake bite.

Jameson Axford remained hospitalized for an eighth consecutive day, but John Axford said his son was able to sleep through the night as he deals with pain. Doctors have saved his right foot, but there is fear one of his toes might need to be amputated.

"It's looking better," Axford said.

Axford said his son was bitten twice last week in the yard of the house his family is renting in Scottsdale, Ariz., for spring training. It happened the same day Axford made his last Cactus League appearance.

Etc.

• First baseman Jon Singleton was among four players optioned to the minor leagues by the Houston Astros, who said rookie Asher Wojciechowski made their starting rotation. Singleton is owed $2 million this year but struck out 18 times in 50 spring training at-bats. The Astros also designated former Twins outfielder Alex Presley for assignment.

• The New York Mets are working to complete a new contract with Juan Lagares that would guarantee the Gold Glove-winning center fielder $23 million from 2016 to '19, including a buyout of a $9.5 million option for 2020.

• Doctors have told Miami reliever Aaron Crow he needs season-ending Tommy John elbow ligament replacement surgery. Crow, 28, went 6-1 with a 4.12 ERA in 61 appearances last season for Kansas City.

• Boston catcher Christian Vazquez will have Tommy John surgery on his right elbow. He had been expected to do much of the catching for the Red Sox this season.

• Washington third baseman Anthony Rendon will start the season on the disabled list because of a sprained left knee. He was hurt March 9 diving for a ball in the field.

• Yankees shortstop Brendan Ryan strained his right calf in New York's 3-0 loss Wednesday to Tampa Bay and is expected to start the season on the disabled list.