Miami Marlins standout right-hander Jose Fernandez faces surgery after it was discovered that the ulnar collateral ligament of his pitching arm is torn.

An MRI on Monday detected the tear and a subsequent examination by noted specialist Dr. Neal ElAttrache of the Kerlan-Jobe Clinic in Los Angeles confirmed it, reported Tuesday. The Tommy John procedure was recommended by ElAttrache. Fernandez was to meet with the team doctor on Tuesday to confirm the diagnosis and treatment. If Fernandez does have the surgery, he can expect a recovery time of 12 to 18 months.

To take Fernandez's place on the roster, the Marlins recalled left-hander Dan Jennings from Triple-A New Orleans. Jennings is 3-5 with a 2.96 ERA with Miami in 79 relief outings spanning the 2011 to 2013 seasons.

Fernandez, the 2013 National League Rookie of the Year, has a 4-2 record with a 2.44 ERA and leads the major leagues with 70 strikeouts so far this season. Last year, Fernandez went 12-6 with a 2.19 ERA and had 187 strikeouts.

---Milwaukee Brewers sluggers Ryan Braun and Amaris Ramirez exchanged places on the 15-day disabled list Tuesday.

Braun, out since April 26 with a strained rib cage, was activated before the game against the Pittsburgh Pirates and Ramirez was put on the DL with a strained left hamstring. Ramriez suffered the injury during the Brewers' 5-4 win over the New York Yankees on Saturday night while fielding a grounder at third base.

In another move, the Brewers recalled utilityman Elian Herrera from Triple-A Nashville and optioned outfielder Caleb Gindl. Herrera was batting .359 for Nashville.

---St. Louis Cardinals left-hander Tyler Lyons was placed on the 15-day disabled list Tuesday with a strained shoulder.

Lyons was roughed up for nine runs on Monday night in a loss to the Chicago Cubs. Since Lyons' call-up from Triple-A in April, he is 0-3 with a 6.12 ERA in six games, including four starts.

To replace the 26-year-old Lyons on the roster, the Cardinals recalled Sam Freeman and Jorge Rondon and also optioned Eric Fornataro to Triple-A Memphis.

---The Kansas City Royals opted to place second baseman Omar Infante on the 15-day disabled list Tuesday because of a bothersome back injury.

The 32-year-old Infante, who signed a four-year, $30.25 million contract during the offseason with the Royals, sat out the past week hoping the back issue would heal enough to avoid a trip to the DL. In 30 games this season, Infante is batting .267 with two home runs and 19 RBIs.

To fill his roster spot, the Royals called up infielder Pedro Ciriaco from Triple-A Omaha.