Jennifer Garner was becoming increasingly worried about Ben Affleck before taking him to rehab for the third time, a source tells ET. 

Garner drove her estranged husband to rehab last week and was photographed arriving at Affleck's house looking visibly upset outside of his Pacific Palisades, California, home. Later, the former couple, along with the actress' bodyguard, was seen driving away from Affleck's house with the Argo director sitting in the backseat, looking distressed.

“Jen was incredibly concerned because Ben was making excuses for missed plans and rarely answering his phone in the week before he entered rehab," our source says. "She knows this pattern very well and became worried.”

According to the source, Garner eventually went to check on 46-year-old Affleck, and the actor appeared to have been on "some type of bender."

“She went over to check on him fearful of what she mind find, and sure enough found him with empty bottles strewn all over the house," the source says. "He reeked of alcohol and clearly had been on some type of bender, and was in terrible shape.”

An eyewitness told ET last week that 46-year-old Garner looked "distraught" as she drove Affleck to rehab. The A-list stars share three children together -- 12-year-old daughter Violet, 9-year-old daughter Seraphina and 6-year-old son Samuel -- and were married for 10 years before splitting in 2015.

"Garner was very emotional but decided to take the situation into her own hands," the eyewitness said. "She looked distraught."

A source later told ET that Garner was relieved Affleck is now in a "safe place."

"This has been a rough few days and [Jennifer] wants nothing more than to feel [Ben] is getting the help that he needs," the source said, adding that Garner has "been Ben's rock" throughout this process. "She is used to putting on a brave face and handling Ben's addiction, but the process has been very exhausting for her. She won't give up on Ben because he is the father of her kids."

"Ben trusts Jen entirely and followed Jen's instructions," the source added. "This time he sounded willing and ready on all counts. Friends who saw Ben's rapid decline are breathing a huge sigh of relief. They have high hopes for a recovery."

For more on how Garner has supported Affleck over the years, watch the video below:

-- Reporting by Adriane Schwartz

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