From 2005-2011 Haren put up a 3.49 ERA and a 122 ERA+ for the Athletics, Diamondbacks and Angels. Nobody in baseball made as many starts during those seven years than Haren's 237, and his 1581⅓ innings were second only to C.C. Sabathia.
But that durability stared to crack in 2012 when Haren missed two and a half weeks with back stiffness, his first career stint on the disabled list.
The Angels after 2012 declined Haren's $15.5 million option, though they nearly came to an agreement to trade Haren to the Cubs for then-closer Carlos Marmol. A year later, the Dodgers have seen both ends of that transaction.
After Haren signed a one-year deal with the Nationals, he stood at the end of June at 4-9 with a 6.15 ERA with a six-game losing streak and seven home runs allowed and a 9.82 ERA in June. Patrick Reddington of Federal Baseball wrote in August for MASN about Haren's early struggles in 2013:
Haren would later admit that after a stretch of particularly rough starts in June, in which he had a 9.82 ERA and seven home runs (3.44 HR/9) allowed in 18 1/3 innings, he worried that he was a bad outing or two away from being released. He reluctantly agreed to the second DL stint of his career, with the Nationals describing the issue as shoulder weakness. Davey Johnson told reporters he hoped the rest would help Haren come back in the second half as he had in 2012, though the issues he was dealing with in each instance were seemingly unconnected.
Haren did rebound, with a 2.16 ERA over his next nine games, including eight starts, and a 3.29 ERA over the final three months of the year, with just nine home runs allowed in 15 starts after 19 homers allowed in his first 15 starts. Nationals manager Davey Johnson described the turnaround, again per Reddington:
"He had a bigger spread in his pitches, which is great," his manager told reporters after Haren's second start following the DL stint. "I think that's more him."
Haren's command improved, as well, with less balls left up in the zone and a corresponding drop in home runs surrendered. Johnson liked what he saw.
"Much better," Johnson said, "And, I mean, very consistent. He didn't have any blips on the screen, like one bad inning where that came up. He was outstanding."
Haren's fastball, which averaged 88.9 mph in 2013, is down a tick or two from his halcyon days of 2005-2011, but the difference in his split-fingered fastball can be seen per FanGraphs:
From the first half in 2013 to the second half, Haren's splitter went from the 86-mph range down to the 82-mph range. The variance may not seem like much, but the more differentiated from his fastball the more effective both pitches become.
Will the Dodgers get a healthy and productive Haren in 2014? For a one-year, $10 million flier, it seems like a worthy gamble to try and find out.