Report: Boston lefty Johnson goes on DL

Brian Johnson, the No. 4 Red Sox prospect, was placed on the seven-day disabled list Monday after experiencing tightness in his elbow, according to the Boston Globe.

Johnson, 24, left his start with Triple-A Pawtucket on Sunday after throwing 60 pitches over four innings. He allowed a run on two hits. He threw 34 of his pitches for strikes while walking three batters. The Globe said the left-hander would undergo evaluation tonight and Tuesday.

Pawtucket has not yet confirmed the move.

Boston's first-round pick in 2012 is 9-6 with a 2.53 ERA in 18 starts this year at Triple-A. He's struck out 90, walked 32 and allowed just six home runs in 96 innings.

The Florida product made his Major League debut on July 21, surrendering four runs in 4 1/3 innings against Houston before returning to the International League for his last two starts. The 2015 IL All-Star has allowed two earned runs or fewer in eight of his last 10 Minor League starts.

The Globe said Boston had been considering calling Johnson back to Fenway some time this week, but will hold off until more is known on his left elbow. In his career, Johnson is 24-15 with a 2.32 ERA in 66 starts since 2012.