Plagued by cap constraints, and lacking an effective reserve floor general, the Oklahoma City Thunder should consider signing a value free-agent point guard to add stability when NBA usage-leader Russell Westbrook sits.

These five quality backups hit the market July 1.

1) Ty Lawson: Kings, UFA: Last season with Sacramento, 29-year-old Lawson experienced an on-court rebirth (9.9 ppg, 4.9 apg, 25.1 mpg, 69 GP) while earning the veteran minimum $1.3 million deal.

If teams aren’t dissuaded by Lawson’s past extracurricular issues, the eight-year-veteran may command between $5-10 million this summer. In an ideal scenario of economy, however, OKC would entice Lawson to guide its reserve-unit and provide valuable minutes alongside Westbrook.

Though, amid intrigued suitors, a Lawson signing isn’t probable, but it isn’t entirely unrealistic. Due to financial restraints, acquiring Ty Lawson would enhance Presti’s resume —provided Lawson focuses solely on basketball.

2) Ramon Sessions: Hornets, Team Option: On the wrong side of 30, and declining, Sessions (6.2 ppg, 2.6 apg, 16.2 mpg —each career lows) would still represent a stark second-unit PG upgrade for the Thunder.

Throughout his serviceable ten-year career, Sessions has averaged 10.6 ppg, and 4.1 apg. It is this experience that will make the 663-game veteran a fine minimum-contract pickup for any team —such as OKC— in need of steady reserve floor-generalship.

Grizzled and mentally tough, Sessions should appear on Presti’s radar as an ideal culture fit.

3) Shelvin Mack: Jazz, UFA: Mack has solidified his NBA niche as a physical, defensive-minded backup who adds just enough offense in select minutes. While a combo-guard of sorts, Mack averaged respectable numbers (7.8 ppg, 2.8 apg, and 0.8 spg) in 55 contests last season for division-rival Utah.

After earning just $2.4 million during the 16-17’ campaign, Mack’s asking price will no doubt rise as the 27-year-old is now established among the league’s better backup PG’s.

If Presti can loosen wiggle room, Mack’s presence in a Thunder uniform would boost the backcourt’s all-around stead.

4) Raymond Felton: LAC, UFA: Another former starter, turned reserve on the veteran’s minimum, perhaps Felton is worth a one-year tender from Oklahoma City.

Last season, behind Chris Paul, Felton added 6.7 ppg and 2.7 apg in 21.3 mpg. At 32 and with eleven years of NBA service, Felton could help steady OKC’s inexperienced bench nucleus.

5) Jose Calderon: Hawks, UFA: Available after the trade-deadline, but passed over for ineffective Norris Cole, Calderon, 35, averaged 7 points and 3.5 assists in Atlanta’s two playoff wins vs. Washington.

Calderon’s post-season heroics proved that he still has tread left on his well-worn wheels.

But is that enough for Sam Presti to bring the two-time Olympic Silver Medalist into Oklahoma City’s fray for 82 games?

Any of these free-agents could potentially remedy Oklahoma City’s glaring performance decline when MVP-finalist Russell Westbrook leaves the floor.

Last year, in addition to usage, by way of historical dominance and inept replacement support, Westbrook also led the NBA in vorp (12.4).

With those statistical markers, it is no surprise that Oklahoma City staggered egregiously (-21.2 Ortg, +41.6 Opp. Ortg) as Westbrook took 13.4 mpg of rest.

Without question, top priority for the Thunder offseason should include aggressively pursuing, and signing, a competent backup point guard to lighten Westbrook’s load and upgrade the team’s greatest shortcoming.