After news of an agreement came to light earlier this week, the Mariners made official their signing of free-agent catcher John Buck to a one-year contract on Thursday afternoon. According to sources, Buck will make $1 million next season.

“Everybody we talked to about him, I heard nothing but really good things,” said general manager Jack Zduriencik. “He’s a true pro and great teammate.”

Buck will likely serve as the backup to touted catching prospect Mike Zunino. Although Zunino is presumed to be the Mariners’ catcher of the future, there is no guarantee that his path won’t have bumps or setbacks. He’s played in just 52 major-league games, hitting .214 with five homers and 14 runs batted in, and he missed almost a month with a broken wrist. Before that, he’d played in just 83 minor-league games. He was fast-tracked to the big leagues because of Jesus Montero’s failures.

Buck, 33, has appeared in 993 major-league games as a catcher in 10 seasons. In 2010 with the Toronto Blue Jays, he earned All-Star honors, hitting .281 with 20 homers and 66 RBI while posting an .802 on-base-plus-slugging percentage.

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To make room for Buck on the 40-man roster, outfielder Carlos Peguero was designated for assignment.

Peguero’s DFA loomed this offseason. He was out of Class AAA options and would have had to make the big-league roster out of spring training, which seemed unlikely.

Peguero still has power potential, but hasn’t quite figured how to use it at the major-league level.

There was also the issue of Peguero’s wife being charged with federal wire fraud after racking up more than $150,000 in charges on Felix Hernandez’s wife’s credit card. Her case is still pending. The Mariners have 10 days to trade, outright or release Peguero.