Rookie right-hander Javier Assad persuaded Cubs manager David Ross to let him pitch the eighth inning Saturday, based on his perfect seventh and a dominant performance in the World Baseball Classic for his native Mexico last month.
Even with more experienced relievers rested and available, Ross stuck with Assad until it was too late, as evidenced by the first three batters that reached base and eventually scored. That transformed a one-run lead into a 3-1 loss to the Brewers before 31,363 chilled fans at Wrigley Field.
‘‘I had no hesitation to send him out there,’’ said Ross, pointing out that Assad was scheduled to face the bottom of the Brewers’ order after breezing through the middle of the lineup.
Before the game, Ross said the roles of his relievers were ‘‘undefined,’’ with the likely exceptions of Brad Boxberger and Michael Fulmer, whose well-located breaking pitch to William Contreras still landed in front of defensive replacement Miles Mastrobuoni in right field for a tiebreaking two-run single with two outs in the eighth.
The Cubs’ bullpen has the flexibility of long relievers such as Assad and Adbert Alzolay, who is extremely effective against right-handed batters, as well as Mark Leiter Jr. and Boxberger against left-handers.
Assad, 25, who has been a starter for most of his career, posted a 1.42 ERA with 12 strikeouts and three walks in 12 2/3 innings covering spring training and the WBC. His velocity also climbed from 92 mph last fall to 97 mph in a WBC game against the United States.
With the Cubs protecting a 1-0 lead in the eighth, however, Assad allowed a single to Brian Anderson and walked pinch hitter Garrett Mitchell on four pitches, even though Mitchell tried to sacrifice early in the count.
‘‘You hate to put it on one moment,’’ Ross said. ‘‘You’ve got to take the outs when we can get them.’’
A single by pinch hitter Jesse Winker tied the score and wiped out Justin Steele’s bid for a well-deserved victory. Steele limited the Brewers to three hits and struck out eight in six innings.
Fulmer was summoned with one out and the score tied and walked Willy Adames to load the bases. After striking out Christian Yelich, Fulmer nearly bailed the Cubs out of further damage. His breaking pitch to Contreras appeared to be out of the strike zone.
Contreras, however, hit a flare to shallow right. Mastrobuoni, who had replaced Trey Mancini to start the inning, appeared to get a late break that proved costly.
Mastrobuoni split most of his time in the minors in the Rays’ organization between second base and the outfield, but he was making only his second appearance in right at Wrigley. He didn’t use the wind, which was gusting at 23 mph at first pitch and persisted, as an excuse.
‘‘For some reason, I shut it down in my head,’’ Mastrobuoni said. ‘‘But looking back on it, I definitely wanted to dive and leave all the uncertainty out there.
‘‘I think [I was] maybe a little late on the jump. I thought I had a good track on it, but it was pushing away from me.’’
