The United States international made the switch to the Britannia Stadium in a reported £2.5million deal from Major League Soccer outfit FC Dallas in January 2013.
Shea has been blighted by a series of injuries that have hindered his progress at the Premier League club, with the 23-year-old limited to just three league appearances from the substitute bench in his first year in England.
He goes straight into Barnsley's starting XI for their visit to Birmingham City, with the Yorkshire outfit looking to move off the foot of the Championship table.
Danny Wilson goes in search of his first three points since returning to Oakwell for his second stint in charge.
Shea is the second player from Stoke to join Barnsley on a temporary basis this season, after goalkeeper Jack Butland made 13 appearances during his loan spell earlier in the season.
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