Short answer. Generally, no. Rule 9, Section 2 of the Rules of Court is direct on this: “a compulsory counterclaim, or a cross-claim, not set up shall be barred.” If your claim against your co-defendant was a cross-claim that belonged in that same case and you never raised it there, the rule treats it as forfeited.
What the law says
A compulsory counterclaim, or a cross-claim, not set up shall be barred.
Rule 9, Section 2 — Compulsory counterclaim, or cross. Read the full provision →
What the rule says
Rule 9, Section 2 is short but absolute: "a compulsory counterclaim, or a cross-claim, not set up shall be barred." It covers two related situations — a compulsory counterclaim a defendant has against the plaintiff, and a cross-claim one party has against a co-party in the same case, such as a claim you had against your co-defendant. In both, the rule's consequence is the same: failing to raise the claim while the case is pending means losing the ability to raise it afterward.
A cross-claim against a co-defendant
A cross-claim, in this context, is a claim you have against someone who is on the same side of the case as you — your co-defendant — rather than against the opposing party. If that claim arises from the same case you were both named in, the rule requires it to be set up within that case rather than saved for a separate lawsuit later. This is what makes the rule relevant here: the claim you describe against your co-defendant is exactly the kind of claim Section 2 is addressing.
What "barred" means
"Barred" means the claim is treated as lost, not merely inconvenient to bring up again. The rule does not say the claim becomes harder to prove, or that you need special permission to raise it — it says the claim shall be barred if it was not set up in the original case. That is a strong consequence, and it reflects the purpose behind requiring these claims to be raised together with the main case: so that everything connected to the same dispute is resolved once, rather than being split across separate proceedings.
Why this matters going forward
If the claim you had against your co-defendant genuinely belonged in that earlier case and was never raised there, Rule 9, Section 2 stands as a real obstacle to suing on it separately now. The practical lesson from this rule is that claims connected to a pending case, especially against a co-party, need to be brought while that case is still active — waiting and filing them afterward as an independent action runs directly into the bar this rule creates.