Lefthander J.A. Happ will be Jordan Lyles' replacement in the Astros starting rotation.

Astros manager Brad Mills said Tuesday that the team will recall Happ from Class AAA Oklahoma City in time to start Friday's game against the San Francisco Giants. Righthander Henry Sosa will come back on three days' rest to take what would have been Lyles' Thursday turn in the rotation.

The Astros optioned Lyles, 20, to Oklahoma City this past Sunday as a means of limiting his work load. While Lyles works out of the bullpen the rest of the season, Happ will get a chance to re-establish his worth as a starter.

Happ, acquired in the 2010 trade that sent Roy Oswalt to the Phillies, got sent down on Aug. 5 with a 4-14 record and 6.26 ERA. In three starts with Oklahoma City, Happ was 1-0 with a 1.50 ERA.

"We wanted to make sure we saw some progress," Mills said. "With us needing a starter on that day, it was a pretty easy call to have him come back up and make his starts up here."

Happ allowed 11 hits and nine walks in 18 innings at Oklahoma City, striking out 16. Astros general manager Ed Wade said Happ, 28, had been earmarked for a spot in the rotation before allowing one hit in seven scoreless innings against Iowa this past Sunday.