He will, I believe, recover completely.
在该句子中，will cecover completedy 是不是谓语？
可以。例如：
You can, if you like, take it home.
= If you like, you can take it home.
= You can take it home, if you like.
如果你喜欢，可以把它拿回家。（摘自《刘毅英语语法宝典》p.652）
