CHICAGO -- Pedro Strop did not hide his emotions on the Wrigley Field mound in the ninth inning Monday night. After his typically precise arm betrayed him and an array of pitches seemed allergic to the strike zone, the Cubs' reliever was shaking his head with expressions of confusion and frustration.

Walks have been an affliction for the Cubs’ bullpen at times this season, but Strop has been mostly immune to the problem. That changed at the worst possible time against the Marlins, who dealt the North Siders a 6-5 loss that was hung on Strop's pitching line. His command issues, combined with an ill-timed decision by lefty Kyle Ryan, put the period on Chicago's seven-game winning streak.

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"I felt really good about Stropy there in the ninth," Cubs manager Joe Maddon said. "He's been so wonderful. That was just unusual."

The Cubs' bullpen has been a strength in recent weeks, but the group still entered Monday night tied for the highest walk rate (13.4 percent) among Major League relief corps. That was hardly impacted by Strop's 5.4 percent walk rate (two in 37 batters faced. The right-hander has a reputation for pounding the strike zone and then often punctuating big moments with animated fist pumps.

There was no questioning the move to hand Strop the ball with a 4-3 lead in the ninth inning against the Marlins. After eight of his first 11 pitches went for balls -- resulting in consecutive walks to Curtis Granderson and Jon Berti -- Strop looked as though he were questioning why his entire arsenal was abandoning him. Strop threw two-seamers, four-seamers, cutters, sliders. Nothing was reliable.

Maddon was at a loss to explain it.

"I don't know. He was just off," said the manager. "Velocity was down. He was just off. That's what I saw."

Pinch-hitter Neil Walker followed with a single to right field, loading the bases for Rosell Herrera. Strop then handed out another free pass, on five pitches, scoring Granderson to pull the game into a 4-4 deadlock. It marked only the third time in 517 career appearances that Strop walked three in the same game. When Maddon pulled Strop at that moment, it made it the lone game in which Strop had three walks with no outs recorded.

Walks were an unfortunate theme for the night. The Marlins walked 10, but the Cubs produced only one run from those free passes. Chicago’s lineup went 1-for-14 combined after a free pass was issued, creating a situation where the bullpen had very little margin for error in the final frame.

With the bases full of Marlins, Maddon turned to Ryan, who has developed into a key member of Chicago's reorganized relief cast. Entering the night, the lefty had a 57.1 percent ground-ball rate, which ranked 23rd among all qualified MLB relievers. The Cubs desperately needed ground balls in this situation, and Ryan did his part, but not without a critical misstep in the process.

First, Miguel Rojas smoked a 101-mph grounder to the right side of the infield, where second baseman David Bote made an impressive diving stop. Bote's only play was at first, allowing Berti to sprint home from third to put Miami ahead, 5-4. Then, Ryan induced a comebacker to the mound off the bat of Martin Prado.

That is where things went awry.

As soon as the pitch met Prado's bat, Walker was on the move from third base to home. The ball struck the dirt in front of the plate and shot up over the mound. Ryan made a leaping grab, landed and immediately looked to third to spot where Walker was along the line. The runner was midway to the plate.

"I was on contact," Walker said. "As soon as it's hit, even if it's a line drive to the third baseman, we're taking the gamble right there. I saw it hit. As soon as it's hit, I'm gone. If he catches it and throws it home, I just try to stay in the rundown as long as I can, to get the hitter to second."

Ryan had Walker caught and looked poised to fire the ball to catcher Willson Contreras. Instead, the reliever inexplicably spun and threw the ball to first baseman Anthony Rizzo.

"I just froze," Ryan said. "Checked him and it ran through my mind, and I froze."

Rizzo got the out at first and then threw across the diamond to third baseman Kris Bryant, who tagged Herrera out to end the inning. Before that third out, though, Walker scored easily to put the Cubs in a 6-4 hole.

That run proved crucial, considering Bryant later launched a towering home run in the bottom of the ninth. Chicago's last-ditch comeback bid did not go any further.

"That's a tough situation to come in in the ninth there," said Rizzo, when asked about Ryan's play. "We all have his back. He's been really good for us since he's been here. ... I'm sure Joe will put him right back in there tomorrow. We have all the confidence in the world in him."