Can a pitcher re enter as a pitcher?

If a pitcher leaves the game and is replaced on the line-up (9 men in NL, 10 in AL) no. But a pitcher can be moved to a different position, and return to the pitcher position, so that a different...

yes only if the coach did not take him completely out of the game during the middle of an inning

You cant have two pitchers at the same time but during the game you can call time and swap the pitchers but the pitcher can not be catcher and the catcher can not be pitcher.

The easy answer is the player who was last designated as the pitcher when the timeout was granted. However, time outs are really charged to the coaching staff, not any pitcher. In Major League...

A pitcher is the person who pitches, or throws, the ball to the batter.