Torsten Frings, one of those older former internationals who seem to be flocking to MLS these days, is out for the season.

Toronto FC, which signed Frings last year, announced last week that he will undergo arthroscopic surgery on his hip and sit out the balance of 2012. Thus Frings, 35, failed to play as many games as his age before incurring a serious injury -- he managed 33 league matches for TFC, scoring two goals and registering three assists -- and while his toughness, experience and leadership surely can't be questioned, he didn't do much to lift TFC out of its seemingly perpetual doldrums.

He was also bothered by shoulder and hamstring problems earlier this season, and how much his age contributed to those issues is fodder for speculation, and perhaps, criticism as to how TFC and other MLS teams pay to play these players in the first place. TFC fans and people who cover the team were already wondering a) if he'll be back next year; and b) should he be back next year?

Yet coaches and general managers will always be tempted to make such moves with a liberal policy of international player slots per team. In a way, this can be deemed a reasonable approach, since the risk of signing a player who may not fit in and/or be hit by injuries is lessened by having alternatives available.

But it can also be frustrating to younger players, many of them American, who might otherwise be given a chance. And in many games Frings stood out even if he didn't dominate the play as many expect all Designated Players to do. But, they are also expected to increase their team's potential to succeed.

The thorny question of which players are too old can't be quantified by a number. Marco Di Vaio, 36, has done pretty well for Montreal. He's not too old as long he's producing and staying reasonably healthy, which are really the same parameters as for most players, aside from the biggest stars and young players scaling the development curve.

But since the older foreign players often command a high salary, naturally, the benchmarks are higher, too. In the last weeks of the regular season, and in some cases the playoffs, they will be under scrutiny.

Seattle, which signed German Christian Tiffert last month, is auditioning former Icelandic interational Eidur Gudjohnsen. The Galaxy's trial of Swedish midfielder midfielder Christian Wilhelmsson resulted in him signing a contract.

No team would be more well-set than the Quakes, yet they have brought in English left back Jordan Stewart for a 10-day trial, looking forward perhaps to next year rather than the Sept. 15 roster freeze date after which no changes can be made.

Most of these players are free agents and as such can sign with an MLS team outside of the North American transfer window, which closed last month. Teams looking to upgrade for the playoffs and/or getting a jump on next year are kicking the tires and taking a test drive. If the players are available and willing to go on trial, why not?

Well, if it's that easy, maybe it's too easy.

The policy of eight slots per team has been in force long enough to be re-examined by MLS and U.S. Soccer, which approves such procedures. Both entities are under pressure to enhance their player development programs and if such a large number of foreign slots -- plus green-card holders -- is to continue, it might also be time to look at some youth mandate that would necessitate more young players getting on the field. They, too, need to show they can produce.