PHILADELPHIA -- Ryan Howard is doing a nice job of burying the anxiety. The reigning National League MVP can't wait to return to the Phillies lineup.

In the meantime, he is patiently recovering from a strained left quadriceps, which forced him onto the disabled list on May 13, retroactive to May 10. Some good news came on Sunday, before Philadelphia's game against Toronto, when Howard took ground balls with Phillies third-base coach Steve Smith.

Howard is scheduled to do rehab work with former Phillies trainer Jeff Cooper before embarking on a two-game rehab assignment as a designated hitter with Class A Lakewood on Wednesday and Thursday. Howard said he should be on schedule to rejoin the Phillies on Friday in Atlanta.

"I feel good," Howard said. "I've been feeling all right. I've been running the last couple of days and hitting in the cage. Hopefully, I'll be alright by the 25th. By the way things have been going, I'll be ready."

Then Howard took about 45 minutes of ground balls from Smith. First, the slugger took ground balls on his knees, then fielded grounders standing at first base. He looked fluid, with no strain or pain.

"It felt good," Howard said after the workout. "I had to get a little used to my depth perception. But otherwise, it was good."

Smith felt the same.

"Ryan did look pretty good," said Smith, who also handles the infield for the Phils. "He told me he felt great taking ground balls. I told him, 'That's nice to see all of the time,' because he looked so smooth. I didn't move him that much, but that will come with a little more time. Ryan is a worker. We did some knee drills, and Ryan's hamstrings were good."

It was encouraging news for manager Charlie Manuel.

"Ryan was having problems putting weight on his backside foot, and it definitely played a role in how he was playing," Manuel said. "It affected his whole game. When Howard originally [strained] it, he didn't think it was that serious. I didn't think a whole about it myself at first.

"We started seeing some things, and Ryan is the kind of player who wants to play every day. But it just came to a point we felt it was better for Ryan and better for the team to get him rested and have this heal, before it got worse. We want him for the long haul."

Castro sent to Double-A: After Sunday's game, the Phillies optioned Fabio Castro to Double-A Reading. The move leaves the Phils without a left-handed reliever in the bullpen.

"Fabio needs to pitch more," Manuel said. "I see him as a situational left-hander, and I think he reminds me of Ricardo Rincon [who Manuel managed in Cleveland], only I think Fabio has better stuff. He just needs a bit more experience."

The Phillies have not announced a move to replace Castro, but there is a strong chance Ryan Madson will be recalled from Reading after two innings and giving up three hits and no runs in a rehab appearance on Sunday. Madson was placed on the 15-day disabled list with a left oblique strain on May 5, retroactive to May 4.

Filling in nicely: Since Howard was placed on the DL, Greg Dobbs has been a credible replacement at first. He was hitting .400 (12-for-30), with a double, triple, two homers and five RBIs over the last 10 games, including an RBI single in the third inning of Sunday's game against Toronto.

This is the longest stretch Dobbs has started in the Majors.

"For me, all I can control is when I'm in there," said Dobbs, 28, who is tied for the Major League lead with six pinch-hit RBIs. "The ultimate goal is to help the team win. I know my role. Once Howard gets back from the DL -- I mean, he's such an offensive force, I'll be back to my role of coming off the bench as a late-inning, left-handed pinch-hitter. This is the longest stretch I've ever played as a starter, and I'm enjoying every second of it. Right now, I'm taking it one day at a time and smelling the roses."

Manuel has been very please with Dobbs. Manuel had a feeling he could produce from Spring Training and saw some things in Dobbs he likes about hitters.

"Dobbs has a great swing and his approach is great; he has a basic, good setup," Manuel said. "Dobbs has a hitter's mentality, which is something I like."

Nunez's glove: The Phillies entered the series finale against Toronto on Sunday with a 6-3 record on the homestand. Part of that success has to be credited to the sterling third-base play of Abraham Nunez.

"I'm just happy to be getting the opportunity to play," said Nunez, who was hitting .317 entering Sunday's game. "I think playing defense is a reaction thing. You have to know the pitch and be prepared for every situation. It's also about getting into a rhythm, too."

Coming up: Philadelphia begins a six-game road swing in Florida on Tuesday at 7:05 p.m. ET. The Phils will go with Cole Hamels (6-1, 3.30 ERA) in the opener. In his last start, he went eight strong innings in a 6-2 victory over Milwaukee, striking out 11 while giving up just one walk. Hamels has a 2-1 lifetime mark against Florida, with a 3.00 ERA. Lefty Scott Olsen (3-3, 4.80 ERA) starts for the Marlins.