4:07pm: The Twins will receive left-hander Kris Johnson from the Pirates in exchange for Welker, the teams have announced via press release.

Johnson, 29, seems to have a shot at making some starts for the Twins at some point next season after pitching to a 2.39 ERA with 6.2 K/9 and 2.9 BB/9 in 135 2/3 innings for the Pirates' Triple-A affiliate in 2013. That will, of course, depend on how the Twins' offseason hunt for pitching shakes out, but few teams have less rotation stability than the Twins. MLB.com's Rhett Bollinger spoke with GM Terry Ryan, who said the team plans to leave Johnson in a starting role (Twitter link).

Like Welker, Johnson made his big league debut with the Bucs in 2013, making three relief appearances and one spot start. After allowing two runs in six innings of relief work in his debut, Johnson was torched for five runs in just two innings in a spot start versus the Cardinals.

Johnson, who is represented by agent Matt Sosnick, was originally selected by the Red Sox with the 40th overall pick in the 2006 draft as compensation for the loss of Johnny Damon via free agency. He signed as a minor league free agent with the Pirates following the 2011 season and has enjoyed his two most successful minor league seasons with Pittsburgh since.

3:48pm: Just six weeks after trading him to the Twins as part of the return for Justin Morneau, the Pirates have reacquired right-hander Duke Welker from Minnesota, according to Jeff Passan of Yahoo Sports (on Twitter). It's unclear what the Twins are receiving in return at this point, Passan adds.

Welker, 27, was acquired as a player to named later in the Morneau deal. The Pirates also sent outfielder Alex Presley to Minnesota as part of the trade. Welker posted a 3.57 ERA with 9.3 K/9 and 4.4 BB/9 in 63 Triple-A innings this season and made his Major League debut with the Pirates, hurling 1 1/3 scoreless innings.

After a five-year absence from the Pirates' Top 30 prospect lists (per Baseball America), Welker resurfaced at No. 26 prior to the season. Drafted in the second round as a starting pitchers, a slew of injuries derailed his prospect status for a number of years. BA wrote this past offseason that since converting to a reliever, Welker's fastball had topped out at 98 mph and he could emerge as a setup man for the Buccos.