Third baseman Martin Prado homers against the Nationals on return from six weeks on disabled list.

The captain is back. Marlins third baseman Martin Prado was activated off the disabled list on Thursday afternoon, after completing a six-week recovery from a left hamstring strain. Prado was in Miami’s lineup Thursday night at third base and hitting fifth.

Prado’s activation was one of four roster moves the Marlins made on Thursday. Right-handed reliever Tayron Guerrero was placed on the 10-day disabled list retroactive to Wednesday with a left lumbar strain. The club also designated outfielder JB Shuck for assignment and recalled righthander Ben Meyer from Triple-A New Orleans.

Prado’s return is a welcome one for the Marlins, who missed the veteran for most of last season with leg injuries. The 34-year-old played just 37 games last year and missed the first month of this season while recovering.

He’s struggled this season in limited action, slashing .194/.242/.226 in 99 plate appearances. All three numbers would be career lows.

Guerrero was pitching well for the Marlins recently, without yielding an earned run in his last eight appearances. Across that stretch, he struck out 12 in nine innings.

Shuck was used mostly as a pinch-hitter in Miami, but also drew starts in all three outfield spots. He had two four-hit games for the Marlins, but had an on-base plus slugging percentage of just .486.

The Marlins are also expected to activate first baseman/outfielder Garrett Cooper this weekend in Washington. He has not played in the majors since April 1 due to a right wrist bruise. mdefranks@sun-sentinel.com; On Twitter @MDeFranks.