"Tommy came out of his bullpen feeling good, and we're going to pencil him in for Tuesday," Angels manager Mike Scioscia said.
Hanson, 4-2 with a 5.10 ERA on the season, was scratched prior to a June 26 start against the Tigers and placed on the DL with a right forearm strain.
The right-hander threw 59 pitches in 3 1/3 innings during a rehab assignment with Class A Inland Empire on Thursday and will likely be confined to a limited pitch count Tuesday.
"We'll evaluate that, but he should have enough to pitch deep enough into the game," Scioscia said.
While Tuesday's start is big for Hanson, who has made just nine starts this season because of time on both the DL and bereavement list, it is also a good sign for an Angels rotation that needs to step up in the second half.
"I think it's an important first step," Scioscia said. "When you see Weave [Jered Weaver] and C.J. [Wilson], hopefully Jerome [Williams] getting back on track, we've got some guys that can help us do what we need to do in the second half, but it's going to take five."
Once Hanson is activated Tuesday, the Angels will have four-fifths of their original rotation back in the mix. Vargas, who had a blood clot in his left armpit, is expected back in either late July or early August.
"I think the biggest thing is getting depth back in our rotation," Scioscia said. "You can talk about needing a sixth and seventh, but at this point in the season, we need one through five. We need those guys to get it going for the second half and we're not quite there yet."
William Boor is an associate reporter for MLB.com.