OAKLAND -- The Angels finally have some positive injury news.

A day after placing four players on the disabled list, bringing their total to a club-record 15, the Angels activated shortstop Andrelton Simmons from the 10-day disabled list Saturday.

It wasn't all good news, however, as left fielder Justin Upton was scratched less than an hour before first pitch Saturday with lower back stiffness. He was replaced in the lineup by Chris Young.

Saturday was the first day Simmons was eligible to return, after sustaining a right ankle sprain slipping on the dugout steps before the June 5 game against the Royals. He started at shortstop and batted second against the A's.

The Angels also optioned infielder Nolan Fontana to Triple-A Salt Lake, called up pitcher John Lamb to start Saturday's game against the A's and designated reliever Oliver Drake for assignment.

When a player's contract is designated for assignment -- often abbreviated "DFA" -- that player is immediately removed from his club's 40-man roster, and 25-man roster if he was on that as well. Within seven days of the transaction (it was previously 10 days), the player must either be traded, released or placed on irrevocable outright waivers.

Simmons made the trip to Oakland on Friday, running the bases and taking batting practice before the Angels' 8-4 win. Manager Mike Scioscia said that Simmons' recovery was slow at first, but improved rapidly.

"Last few days, it's just gone at light speed," Scioscia said. "Feel like he has all his mobility. Moving well, running well."

The three-time Gold Glove winner's return gives the Angels a boost offensively and defensively. Simmons is second in the American League among shortstops with a .330 batting average, and his .399 on-base percentage is second on the team only to Michael Trout .

"The way he was doing so many things, not just on the defensive end, which you see, but on the offensive end -- his versatility, the way he was getting on base, hitting the ball while using the whole field -- that was an important move to get back," Scioscia said.

Even with Simmons in the lineup, the Angels are still without right fielder Kole Calhoun (oblique) and shortstop Zack Cozart (left shoulder subluxation), who was filling in for Simmons at shortstop, but went on the 10-day disabled list Friday.

"If you look at the offensive side of our club, you take out Kole, Zack, Andrelton, there's a huge part of your club that's not in there, so to get one piece back is important," Scioscia said.

Fontana has one hit in 12 plate appearances this season. Drake appeared in four games this season and was 0-1 with a 10.13 ERA.