Following Saturday's win, the Mets recalled Nelson Figueroa from Triple-A Buffalo to start in Pelfrey's place and designated reliever Darren O'Day for assignment. O'Day is a Rule 5 Draft pick, which means he has to be offered back to his original team, the Angels.
Given the Brewers' right-handed-heavy lineup, the right-handed Figueroa was the logical choice for the spot start. A fill-in starter for the Mets last season, Figueroa last pitched on Thursday but was pulled after only two innings.
In two games at the Triple-A level this year, Figueroa has a 3.00 ERA over nine innings. He was 3-3 with a 4.57 ERA in 16 Major League games last season.
Given how early in the season it is, Manuel reiterated that Pelfrey's condition isn't serious and the Mets are just being extra careful.
"If this was September, he would pitch, no question about it," Manuel said.
In lieu of his start, Pelfrey still may pitch, although the Mets would certainly like to avoid that scenario.
Manuel said beginning with Tuesday's opener in St. Louis, Pelfrey would be available out of the bullpen if the team encounters an "emergency situation". In other words, if Pelfrey is the last man in the bullpen, Manuel wouldn't hesitate to use the big right-hander.
The Mets prodded Pelfrey to have his arm examined following his performance April 13, during which he allowed five earned runs and eight hits in five innings.
In his first two starts this season, Pelfrey has walked six batters, allowing nine earned runs in 10 innings en route to an 8.10 ERA.
Although Pelfrey shied away from using his injury as a crutch for his early-season struggles, Manuel believes getting him the rest in April will prevent any further issues.
"We have to explain to him the big picture," Manuel said. "Now we don't anticipate, we don't expect any more setbacks."
Both Manuel and Pelfrey were confident that the tendinitis would only sideline Pelfrey for one start and wouldn't develop into a lingering situation.
"My arm feels better already," Pelfrey said on Saturday.
He is expected to continue treatment throughout the week, and is tentatively scheduled to make his next start April 25.
Brittany Ghiroli is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.