The same caution that applies to financial services applies to major-league bullpens: Past performance is no guarantee of future success.
Relief pitching is the most fickle aspect of any baseball team. Injuries, the accumulation of innings and changes in performance force even the best of teams to parade reliever after reliever through their bullpens year after year.
Even while winning a world championship last year, the Chicago Cubs had their issues. They capitalized on the market in July, obtaining lightning thrower Aroldis Chapman as their second-half and postseason closer. They drained all they could from Chapman before he returned to the New York Yankees as a free agent.
There were other issues. Displaced closer Hector Rondon and top setup man Pedro Strop were slowed by injuries late in the season, and neither was the same after coming back. Both are back in camp and professing to be healthy.
Chapman has been replaced by dependable and low-key closer Wade Davis, who was obtained from the Kansas City Royals in a trade for outfielder Jorge Soler.
Lefty Travis Wood signed with the Royals, and his role will be filled by fellow left-hander Brian Duensing. Right-hander Justin Grimm is back, and the Cubs took a chance on righty Koji Uehara, who turns 42 on April 3. They'll join a mix that includes intriguing youngster Carl Edwards Jr., who got 10th-inning experience in Game 7 of the 2016 World Series.
Another reminder: The bullpen a team starts the season with is rarely the one that finishes the season.
The man to watch is Davis. The Cubs gave up a promising young position player for Davis, who can become a free agent after this season.
Last year Davis saved a career-best 27 games (in 30 chances) in going 2-1 with a 1.87 ERA and a WHIP of 1.13. During the Royals' world-championship season of 2015, Davis was 8-1 with an 0.94 ERA, 17 saves and a WHIP of 0.79. He served two stints on the disabled list last year with forearm and flexor strains.
Through Sunday's Cactus League action, Davis had pitched 2 ⅓ innings in three games, giving up 6 hits and 4 runs.
"It's definitely a blessing to be on a team that's this young and motivated and talented," said Davis, who was moved to the bullpen by now-Cubs manager Joe Maddon in Tampa Bay for the 2011 postseason and then full time for the 2012 regular season.
Maddon described Davis as "physically gifted" and that his stuff got better when he became a reliever.
"His stuff is above and beyond, especially when we put him in the bullpen and he stayed there on a more consistent basis, you see the velocity, the break and all that kind of stuff," Maddon said. "There was definitely an uptick from starting to relieving. You'd see flashes of that as a starter. You see it more consistently stuff wise as a reliever.
"And the other side, this incredible calm about him. That's a big part of what plays so well in the bullpen, the fact that he is able to process the moment so slowly."
Let's not forget Rondon. In the past three years with the Cubs, he piled up 77 saves (30 in 2015). He went on the disabled list last Aug. 19 with a right triceps strain. In the final month of the season, he had a 9.82 ERA and a WHIP of 2.05.
Strop hurt his knee in August and then suffered a groin injury while rehabbing the knee. He was out for more than a month. In the early days of this year's spring training, he signed a one-year contract extension through 2018.
If both Strop and Rondon can return to form, the Cubs will boast a deep back of their bullpen.
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