Rodriguez was arrested and being held at the ballpark early Thursday, police explained. His father-in-law was in a hospital using a scrape on his face and also a bump on his head.
"There was an incident at the ballpark among Francisco Rodriguez and his family members. He was questioned by police and all other questions pertaining to this matter could be addressed to police," Mets spokesman Jay Horwitz mentioned.
Many security guards, along some women and kids, were observed around the Mets' loved ones lounge near the clubhouse following New York's 6-2 loss to Colorado. Rodriguez's father-in-law had swelling above his proper eyebrow.
Rodriguez has had previous confrontations with a team official, a coach and an opponent in his 1 1/2 seasons with all the Mets, though none of them reached this level.
The excitable, 28-year-old pitcher signed a three-year, $37 million contract using the Mets soon after posting a record 62 saves using the Angels in 2008. He is 4-2 with 25 saves along with a two.24 ERA this season.
Rodriguez did not pitch in the Mets' latest loss, which dropped them below .500. Reliever Manny Acosta gave up a two-out grand slam to Melvin Mora inside eighth inning.
In May possibly, Rodriguez and bullpen coach Randy Niemann got into a heated exchange whilst the pitcher was preparing to enter a game. Mets manager Jerry Manuel later mentioned the matter was resolved, with no divulging what caused the dispute.
In July 2009, Rodriguez and former Mets official Tony Bernazard argued aboard the team bus. Bernazard was later fired by the Mets amid a number of allegations.
That June, Rodriguez and New York Yankees reliever Brian Bruney needed to be separated before a game. They had jawed at each other within the media a day earlier.