Seymour will serve as the Rays' opening pitcher for Monday's game against the Red Sox, Marc Topkin of the Tampa Bay Times reports.
Seymour will likely pitch one or two innings before turning the ball over to right-hander Mason Englert, the latter of whom was recalled from Triple-A Durham on Wednesday. The left-handed Seymour has struggled as of late, allowing seven runs (five earned) on six hits and seven walks while striking out six in 6.2 innings spanning his last four appearances.