Initial hopes were that Matt Harrison would be able to return to the majors on April 24. After his last rehab outing, however, where his velocity was off and the results were disappointing, indications were that Harrison would go tonight for Frisco, and then have at least one more rehab outing.
However, Harrison's performance tonight, combined with Tanner Scheppers going on the d.l., may have the Rangers back to their original timeline. His final line was 8 innings, 3 hits, 1 walk, 5 Ks, and 0 runs allowed. Twitter reports from those at the game were uniformly positive.
Given that the Rangers need someone to come up and start for Scheppers this week, and given that Harrison was outstanding tonight, it seems like it would make more sense for Harrison to return to the majors, rather than bringing up Nick Martinez so that Harrison can make another rehab start. We'll have to wait for the official announcement, but at this point, I'm expecting Harrison's next outing to be in the majors.