The most common and most likely answer to this crossword clue is the 4 letter word BACK
I've seen this crossword clue in The Times
B
A
C
K
More clues leading to the result BACK
Buddy explains!

The straight part
We know that "Second/team player/reinstated?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case second/team player/reinstated? = back.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BACK mean?
BACK noun- The rear of the body, especially the part between the neck and the end of the spine and opposite the chest and belly.
- That which is farthest away from the front.
- Upper part of a natural object which is considered to resemble an animal's back.
- A support or resource in reserve.
- The keel and keelson of a ship.
- The roof of a horizontal underground passage.
- Effort, usually physical.
- A non-alcoholic drink (often water or a soft drink), to go with hard liquor or a cocktail.
- Among leather dealers, one of the thickest and stoutest tanned hides.
- To go in the reverse direction.
- To support.
- (of the wind) To change direction contrary to the normal pattern; that is, to shift anticlockwise in the northern hemisphere, or clockwise in the southern hemisphere.
- (of a square sail) To brace the yards so that the wind presses on the front of the sail, to slow the ship.
- (of an anchor) To lay out a second, smaller anchor to provide additional holding power.
- (of a hunting dog) To stand still behind another dog which has pointed.
- To push or force backwards.
- To get upon the back of; to mount.
- To place or seat upon the back.
- To make a back for; to furnish with a back.
- To adjoin behind; to be at the back of.
- To write upon the back of, possibly as an endorsement.
- (of a justice of the peace) To sign or endorse (a warrant, issued in another county, to apprehend an offender).
- To row backward with (oars).
- Near the rear.
- Not current.
- Far from the main area.
- In arrear; overdue.
- Moving or operating backward.
- Pronounced with the highest part of the body of the tongue toward the back of the mouth, near the soft palate (most often describing a vowel).
- To or in a previous condition or place.
- Away from the front or from an edge.
- In a manner that impedes.
- In a reciprocal manner; in return.
- Earlier, ago.
- A large shallow vat; a cistern, tub, or trough, used by brewers, distillers, dyers, picklers, gluemakers, and others, for mixing or cooling wort, holding water, hot glue, etc.
- A ferryboat.