Free-agent outfielder Nick Castellanos and the Philadelphia Phillies are in agreement on a five-year, $100 million contract, sources familiar with the deal told ESPN's Jeff Passan.

Castellanos, 30, is coming off his best big league season for Cincinnati, a campaign in which he ranked in the top 10 of the National League in several offensive categories. He finished fourth in the NL batting race (.309), hit 34 homers (tied for 7th), drove in 100 runs (tied for ninth), ranked third in slugging (.576) and fourth in OPS .939. He posted a career-best 3.2 WAR, according to baseball-reference.com.

It was a banner season all around for Castellanos. He was elected as a starter for the NL in the All-Star game, won a Silver Slugger award and finished 12 in balloting for NL MVP.

On Nov. 4, Castellanos opted out of the final two years of his contract with the Reds that would have paid him $34 million. Cincinnati then extended Castellanos the qualifying offer of $18.4 million, which he rejected, making him a free agent. As a result, the Reds will get a compensatory 2022 draft pick that will fall after the first round.

After serving as the regular third baseman for the Tigers early in his career, Castellanos has primarily played right field since late in the 2017 season after switching away from the hot corner. Since the beginning of the 2016 season, he ranks 14th among all big league batters in hits (860) and is second in doubles (214).

As strong as Castellanos has been at the plate as a big leaguer, he's often struggled as a defender. According to Fangraphs, Castellanos has posted minus-93 defensive runs saved during his time in the majors. That's the worst figure among all fielders since Castellanos broke into the majors in 2013.

Castellanos, who turned 30 earlier this month, has previously played for the Tigers and Cubs. He was drafted with the 44th pick of the 2010 draft, in a compensation round, out of Archbishop McCarthy High School in Southwest Ranches, Fla., about 30 miles from downtown Miami.

ESPN's Bradford Doolittle contributed to this report.