Scalise, 51, a Louisiana Republican who is the No. 3 House Republican, remained in critical condition at a hospital a few miles from the stadium after undergoing a third surgery on Thursday.
On Friday, the hospital's director of trauma, Dr. Jack Sava, called Scalise's injury a "transpelvic gunshot wound" which had "fragmented, and caused significant damage to bones, internal organs and blood vessels".
During the baseball practice on Wednesday, a gunman opened fire, injuring Scalise, congressional staffer Zach Barth, Tyson Foods lobbyist Matt Mika and two members of the Capitol Police force, Crystal Griner and David Bailey.
Several other people were also injured in Wednesday's shooting before Scalise's security detail and other police officers gunned down the assailant, who later died.
Steve Scalise during practice days before. He added that Scalise would be in the hospital "for some time" and would need "a period of healing and rehabilitation" after being discharged.
Sava said Friday that there were still hundreds of bullet fragments in Scalise's body, but that doctors "have no intention to try and remove all the bullet fragments at this point". His family said in a statement Saturday that Mika had undergone another operation and was expected to recover fully, according to NBC News.
Democrat Cedric Richmond, a fellow Louisiana congressman, said as many others did that Scalise is a fighter.
Sava said he told Scalise's family that "I am not declaring victory until he's playing ball in his back yard with his family".
The president said that because of the "tremendous pain and suffering he's now enduring. our country will perhaps become closer, more unified".
The senior Republican suffered extensive injuries and was in critical condition on Wednesday night. Griner remains hospitalized at MedStar Hospital after getting shot in the ankle, and Sava described her in good condition.
More than $1 million has been raised for charity through the Congressional Baseball Game, its host organization announced Thursday, a day after a shooting unfolded at the Republicans' practice for the game.